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 = [
  51                 'login' => 'ApiLogin',
  52                 'clientlogin' => 'ApiClientLogin',
  53                 'logout' => 'ApiLogout',
  54                 'createaccount' => 'ApiAMCreateAccount',
  55                 'linkaccount' => 'ApiLinkAccount',
  56                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  57                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  58                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  59                 'resetpassword' => 'ApiResetPassword',
  60                 'query' => 'ApiQuery',
  61                 'expandtemplates' => 'ApiExpandTemplates',
  62                 'parse' => 'ApiParse',
  63                 'stashedit' => 'ApiStashEdit',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedcontributions' => 'ApiFeedContributions',
  66                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  67                 'feedwatchlist' => 'ApiFeedWatchlist',
  68                 'help' => 'ApiHelp',
  69                 'paraminfo' => 'ApiParamInfo',
  70                 'rsd' => 'ApiRsd',
  71                 'compare' => 'ApiComparePages',
  72                 'tokens' => 'ApiTokens',
  73                 'checktoken' => 'ApiCheckToken',
  74                 'cspreport' => 'ApiCSPReport',
  75
  76                 // Write modules
  77                 'purge' => 'ApiPurge',
  78                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  79                 'rollback' => 'ApiRollback',
  80                 'delete' => 'ApiDelete',
  81                 'undelete' => 'ApiUndelete',
  82                 'protect' => 'ApiProtect',
  83                 'block' => 'ApiBlock',
  84                 'unblock' => 'ApiUnblock',
  85                 'move' => 'ApiMove',
  86                 'edit' => 'ApiEditPage',
  87                 'upload' => 'ApiUpload',
  88                 'filerevert' => 'ApiFileRevert',
  89                 'emailuser' => 'ApiEmailUser',
  90                 'watch' => 'ApiWatch',
  91                 'patrol' => 'ApiPatrol',
  92                 'import' => 'ApiImport',
  93                 'clearhasmsg' => 'ApiClearHasMsg',
  94                 'userrights' => 'ApiUserrights',
  95                 'options' => 'ApiOptions',
  96                 'imagerotate' => 'ApiImageRotate',
  97                 'revisiondelete' => 'ApiRevisionDelete',
  98                 'managetags' => 'ApiManageTags',
  99                 'tag' => 'ApiTag',
 100                 'mergehistory' => 'ApiMergeHistory',
 101         ];
 102
 103         /**
 104          * List of available formats: format name => format class
 105          */
 106         private static $Formats = [
 107                 'json' => 'ApiFormatJson',
 108                 'jsonfm' => 'ApiFormatJson',
 109                 'php' => 'ApiFormatPhp',
 110                 'phpfm' => 'ApiFormatPhp',
 111                 'xml' => 'ApiFormatXml',
 112                 'xmlfm' => 'ApiFormatXml',
 113                 'rawfm' => 'ApiFormatJson',
 114                 'none' => 'ApiFormatNone',
 115         ];
 116
 117         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 118         /**
 119          * List of user roles that are specifically relevant to the API.
 120          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 121          *                           'params' => array ( $someVarToSubst ) ),
 122          *                          );
 123          */
 124         private static $mRights = [
 125                 'writeapi' => [
 126                         'msg' => 'right-writeapi',
 127                         'params' => []
 128                 ],
 129                 'apihighlimits' => [
 130                         'msg' => 'api-help-right-apihighlimits',
 131                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 132                 ]
 133         ];
 134         // @codingStandardsIgnoreEnd
 135
 136         /**
 137          * @var ApiFormatBase
 138          */
 139         private $mPrinter;
 140
 141         private $mModuleMgr, $mResult, $mErrorFormatter;
 142         /** @var ApiContinuationManager|null */
 143         private $mContinuationManager;
 144         private $mAction;
 145         private $mEnableWrite;
 146         private $mInternalMode, $mSquidMaxage;
 147         /** @var ApiBase */
 148         private $mModule;
 149
 150         private $mCacheMode = 'private';
 151         private $mCacheControl = [];
 152         private $mParamsUsed = [];
 153
 154         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 155         private $lacksSameOriginSecurity = null;
 156
 157         /**
 158          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 159          *
 160          * @param IContextSource|WebRequest $context If this is an instance of
 161          *    FauxRequest, errors are thrown and no printing occurs
 162          * @param bool $enableWrite Should be set to true if the api may modify data
 163          */
 164         public function __construct( $context = null, $enableWrite = false ) {
 165                 if ( $context === null ) {
 166                         $context = RequestContext::getMain();
 167                 } elseif ( $context instanceof WebRequest ) {
 168                         // BC for pre-1.19
 169                         $request = $context;
 170                         $context = RequestContext::getMain();
 171                 }
 172                 // We set a derivative context so we can change stuff later
 173                 $this->setContext( new DerivativeContext( $context ) );
 174
 175                 if ( isset( $request ) ) {
 176                         $this->getContext()->setRequest( $request );
 177                 } else {
 178                         $request = $this->getRequest();
 179                 }
 180
 181                 $this->mInternalMode = ( $request instanceof FauxRequest );
 182
 183                 // Special handling for the main module: $parent === $this
 184                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 185
 186                 $config = $this->getConfig();
 187
 188                 if ( !$this->mInternalMode ) {
 189                         // Log if a request with a non-whitelisted Origin header is seen
 190                         // with session cookies.
 191                         $originHeader = $request->getHeader( 'Origin' );
 192                         if ( $originHeader === false ) {
 193                                 $origins = [];
 194                         } else {
 195                                 $originHeader = trim( $originHeader );
 196                                 $origins = preg_split( '/\s+/', $originHeader );
 197                         }
 198                         $sessionCookies = array_intersect(
 199                                 array_keys( $_COOKIE ),
 200                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 201                         );
 202                         if ( $origins && $sessionCookies && (
 203                                 count( $origins ) !== 1 || !self::matchOrigin(
 204                                         $origins[0],
 205                                         $config->get( 'CrossSiteAJAXdomains' ),
 206                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 207                                 )
 208                         ) ) {
 209                                 MediaWiki\Logger\LoggerFactory::getInstance( 'cors' )->warning(
 210                                         'Non-whitelisted CORS request with session cookies', [
 211                                                 'origin' => $originHeader,
 212                                                 'cookies' => $sessionCookies,
 213                                                 'ip' => $request->getIP(),
 214                                                 'userAgent' => $this->getUserAgent(),
 215                                                 'wiki' => wfWikiID(),
 216                                         ]
 217                                 );
 218                         }
 219
 220                         // If we're in a mode that breaks the same-origin policy, strip
 221                         // user credentials for security.
 222                         if ( $this->lacksSameOriginSecurity() ) {
 223                                 global $wgUser;
 224                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 225                                 $wgUser = new User();
 226                                 $this->getContext()->setUser( $wgUser );
 227                         }
 228                 }
 229
 230                 $uselang = $this->getParameter( 'uselang' );
 231                 if ( $uselang === 'user' ) {
 232                         // Assume the parent context is going to return the user language
 233                         // for uselang=user (see T85635).
 234                 } else {
 235                         if ( $uselang === 'content' ) {
 236                                 global $wgContLang;
 237                                 $uselang = $wgContLang->getCode();
 238                         }
 239                         $code = RequestContext::sanitizeLangCode( $uselang );
 240                         $this->getContext()->setLanguage( $code );
 241                         if ( !$this->mInternalMode ) {
 242                                 global $wgLang;
 243                                 $wgLang = $this->getContext()->getLanguage();
 244                                 RequestContext::getMain()->setLanguage( $wgLang );
 245                         }
 246                 }
 247
 248                 $this->mModuleMgr = new ApiModuleManager( $this );
 249                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 250                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 251                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 252                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 253
 254                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 255
 256                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 257                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 258                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 259                 $this->mResult->setMainForContinuation( $this );
 260                 $this->mContinuationManager = null;
 261                 $this->mEnableWrite = $enableWrite;
 262
 263                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 264                 $this->mCommit = false;
 265         }
 266
 267         /**
 268          * Return true if the API was started by other PHP code using FauxRequest
 269          * @return bool
 270          */
 271         public function isInternalMode() {
 272                 return $this->mInternalMode;
 273         }
 274
 275         /**
 276          * Get the ApiResult object associated with current request
 277          *
 278          * @return ApiResult
 279          */
 280         public function getResult() {
 281                 return $this->mResult;
 282         }
 283
 284         /**
 285          * Get the security flag for the current request
 286          * @return bool
 287          */
 288         public function lacksSameOriginSecurity() {
 289                 if ( $this->lacksSameOriginSecurity !== null ) {
 290                         return $this->lacksSameOriginSecurity;
 291                 }
 292
 293                 $request = $this->getRequest();
 294
 295                 // JSONP mode
 296                 if ( $request->getVal( 'callback' ) !== null ) {
 297                         $this->lacksSameOriginSecurity = true;
 298                         return true;
 299                 }
 300
 301                 // Anonymous CORS
 302                 if ( $request->getVal( 'origin' ) === '*' ) {
 303                         $this->lacksSameOriginSecurity = true;
 304                         return true;
 305                 }
 306
 307                 // Header to be used from XMLHTTPRequest when the request might
 308                 // otherwise be used for XSS.
 309                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 310                         $this->lacksSameOriginSecurity = true;
 311                         return true;
 312                 }
 313
 314                 // Allow extensions to override.
 315                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 316                 return $this->lacksSameOriginSecurity;
 317         }
 318
 319         /**
 320          * Get the ApiErrorFormatter object associated with current request
 321          * @return ApiErrorFormatter
 322          */
 323         public function getErrorFormatter() {
 324                 return $this->mErrorFormatter;
 325         }
 326
 327         /**
 328          * Get the continuation manager
 329          * @return ApiContinuationManager|null
 330          */
 331         public function getContinuationManager() {
 332                 return $this->mContinuationManager;
 333         }
 334
 335         /**
 336          * Set the continuation manager
 337          * @param ApiContinuationManager|null
 338          */
 339         public function setContinuationManager( $manager ) {
 340                 if ( $manager !== null ) {
 341                         if ( !$manager instanceof ApiContinuationManager ) {
 342                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 343                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 344                                 );
 345                         }
 346                         if ( $this->mContinuationManager !== null ) {
 347                                 throw new UnexpectedValueException(
 348                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 349                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 350                                 );
 351                         }
 352                 }
 353                 $this->mContinuationManager = $manager;
 354         }
 355
 356         /**
 357          * Get the API module object. Only works after executeAction()
 358          *
 359          * @return ApiBase
 360          */
 361         public function getModule() {
 362                 return $this->mModule;
 363         }
 364
 365         /**
 366          * Get the result formatter object. Only works after setupExecuteAction()
 367          *
 368          * @return ApiFormatBase
 369          */
 370         public function getPrinter() {
 371                 return $this->mPrinter;
 372         }
 373
 374         /**
 375          * Set how long the response should be cached.
 376          *
 377          * @param int $maxage
 378          */
 379         public function setCacheMaxAge( $maxage ) {
 380                 $this->setCacheControl( [
 381                         'max-age' => $maxage,
 382                         's-maxage' => $maxage
 383                 ] );
 384         }
 385
 386         /**
 387          * Set the type of caching headers which will be sent.
 388          *
 389          * @param string $mode One of:
 390          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 391          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 392          *         not provided by any of these means, the object will be private.
 393          *    - 'private':    Cache this object only in private client-side caches.
 394          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 395          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 396          *         set consistently for a given URL, it cannot be set differently depending on
 397          *         things like the contents of the database, or whether the user is logged in.
 398          *
 399          *  If the wiki does not allow anonymous users to read it, the mode set here
 400          *  will be ignored, and private caching headers will always be sent. In other words,
 401          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 402          *  view.
 403          *
 404          *  For user-dependent data, the private mode should generally be used. The
 405          *  anon-public-user-private mode should only be used where there is a particularly
 406          *  good performance reason for caching the anonymous response, but where the
 407          *  response to logged-in users may differ, or may contain private data.
 408          *
 409          *  If this function is never called, then the default will be the private mode.
 410          */
 411         public function setCacheMode( $mode ) {
 412                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 413                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 414
 415                         // Ignore for forwards-compatibility
 416                         return;
 417                 }
 418
 419                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 420                         // Private wiki, only private headers
 421                         if ( $mode !== 'private' ) {
 422                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 423
 424                                 return;
 425                         }
 426                 }
 427
 428                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 429                         // User language is used for i18n, so we don't want to publicly
 430                         // cache. Anons are ok, because if they have non-default language
 431                         // then there's an appropriate Vary header set by whatever set
 432                         // their non-default language.
 433                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 434                                 "'anon-public-user-private' due to uselang=user\n" );
 435                         $mode = 'anon-public-user-private';
 436                 }
 437
 438                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 439                 $this->mCacheMode = $mode;
 440         }
 441
 442         /**
 443          * Set directives (key/value pairs) for the Cache-Control header.
 444          * Boolean values will be formatted as such, by including or omitting
 445          * without an equals sign.
 446          *
 447          * Cache control values set here will only be used if the cache mode is not
 448          * private, see setCacheMode().
 449          *
 450          * @param array $directives
 451          */
 452         public function setCacheControl( $directives ) {
 453                 $this->mCacheControl = $directives + $this->mCacheControl;
 454         }
 455
 456         /**
 457          * Create an instance of an output formatter by its name
 458          *
 459          * @param string $format
 460          *
 461          * @return ApiFormatBase
 462          */
 463         public function createPrinterByName( $format ) {
 464                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 465                 if ( $printer === null ) {
 466                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 467                 }
 468
 469                 return $printer;
 470         }
 471
 472         /**
 473          * Execute api request. Any errors will be handled if the API was called by the remote client.
 474          */
 475         public function execute() {
 476                 if ( $this->mInternalMode ) {
 477                         $this->executeAction();
 478                 } else {
 479                         $this->executeActionWithErrorHandling();
 480                 }
 481         }
 482
 483         /**
 484          * Execute an action, and in case of an error, erase whatever partial results
 485          * have been accumulated, and replace it with an error message and a help screen.
 486          */
 487         protected function executeActionWithErrorHandling() {
 488                 // Verify the CORS header before executing the action
 489                 if ( !$this->handleCORS() ) {
 490                         // handleCORS() has sent a 403, abort
 491                         return;
 492                 }
 493
 494                 // Exit here if the request method was OPTIONS
 495                 // (assume there will be a followup GET or POST)
 496                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 497                         return;
 498                 }
 499
 500                 // In case an error occurs during data output,
 501                 // clear the output buffer and print just the error information
 502                 $obLevel = ob_get_level();
 503                 ob_start();
 504
 505                 $t = microtime( true );
 506                 $isError = false;
 507                 try {
 508                         $this->executeAction();
 509                         $runTime = microtime( true ) - $t;
 510                         $this->logRequest( $runTime );
 511                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 512                                 $this->getStats()->timing(
 513                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 514                                 );
 515                         }
 516                 } catch ( Exception $e ) {
 517                         $this->handleException( $e );
 518                         $this->logRequest( microtime( true ) - $t, $e );
 519                         $isError = true;
 520                 }
 521
 522                 // Commit DBs and send any related cookies and headers
 523                 MediaWiki::preOutputCommit( $this->getContext() );
 524
 525                 // Send cache headers after any code which might generate an error, to
 526                 // avoid sending public cache headers for errors.
 527                 $this->sendCacheHeaders( $isError );
 528
 529                 // Executing the action might have already messed with the output
 530                 // buffers.
 531                 while ( ob_get_level() > $obLevel ) {
 532                         ob_end_flush();
 533                 }
 534         }
 535
 536         /**
 537          * Handle an exception as an API response
 538          *
 539          * @since 1.23
 540          * @param Exception $e
 541          */
 542         protected function handleException( Exception $e ) {
 543                 // Bug 63145: Rollback any open database transactions
 544                 if ( !( $e instanceof UsageException ) ) {
 545                         // UsageExceptions are intentional, so don't rollback if that's the case
 546                         try {
 547                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 548                         } catch ( DBError $e2 ) {
 549                                 // Rollback threw an exception too. Log it, but don't interrupt
 550                                 // our regularly scheduled exception handling.
 551                                 MWExceptionHandler::logException( $e2 );
 552                         }
 553                 }
 554
 555                 // Allow extra cleanup and logging
 556                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 557
 558                 // Log it
 559                 if ( !( $e instanceof UsageException ) ) {
 560                         MWExceptionHandler::logException( $e );
 561                 }
 562
 563                 // Handle any kind of exception by outputting properly formatted error message.
 564                 // If this fails, an unhandled exception should be thrown so that global error
 565                 // handler will process and log it.
 566
 567                 $errCode = $this->substituteResultWithError( $e );
 568
 569                 // Error results should not be cached
 570                 $this->setCacheMode( 'private' );
 571
 572                 $response = $this->getRequest()->response();
 573                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 574                 if ( $e->getCode() === 0 ) {
 575                         $response->header( $headerStr );
 576                 } else {
 577                         $response->header( $headerStr, true, $e->getCode() );
 578                 }
 579
 580                 // Reset and print just the error message
 581                 ob_clean();
 582
 583                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 584                 $this->createErrorPrinter();
 585
 586                 try {
 587                         $this->printResult( true );
 588                 } catch ( UsageException $ex ) {
 589                         // The error printer itself is failing. Try suppressing its request
 590                         // parameters and redo.
 591                         $this->setWarning(
 592                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 593                         );
 594                         $this->mPrinter = null;
 595                         $this->createErrorPrinter();
 596                         $this->mPrinter->forceDefaultParams();
 597                         $this->printResult( true );
 598                 }
 599         }
 600
 601         /**
 602          * Handle an exception from the ApiBeforeMain hook.
 603          *
 604          * This tries to print the exception as an API response, to be more
 605          * friendly to clients. If it fails, it will rethrow the exception.
 606          *
 607          * @since 1.23
 608          * @param Exception $e
 609          * @throws Exception
 610          */
 611         public static function handleApiBeforeMainException( Exception $e ) {
 612                 ob_start();
 613
 614                 try {
 615                         $main = new self( RequestContext::getMain(), false );
 616                         $main->handleException( $e );
 617                         $main->logRequest( 0, $e );
 618                 } catch ( Exception $e2 ) {
 619                         // Nope, even that didn't work. Punt.
 620                         throw $e;
 621                 }
 622
 623                 // Reset cache headers
 624                 $main->sendCacheHeaders( true );
 625
 626                 ob_end_flush();
 627         }
 628
 629         /**
 630          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 631          *
 632          * If no origin parameter is present, nothing happens.
 633          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 634          * is set and false is returned.
 635          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 636          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 637          * headers are set.
 638          * http://www.w3.org/TR/cors/#resource-requests
 639          * http://www.w3.org/TR/cors/#resource-preflight-requests
 640          *
 641          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 642          */
 643         protected function handleCORS() {
 644                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 645                 if ( $originParam === null ) {
 646                         // No origin parameter, nothing to do
 647                         return true;
 648                 }
 649
 650                 $request = $this->getRequest();
 651                 $response = $request->response();
 652
 653                 $matchOrigin = false;
 654                 $allowTiming = false;
 655                 $varyOrigin = true;
 656
 657                 if ( $originParam === '*' ) {
 658                         // Request for anonymous CORS
 659                         $matchOrigin = true;
 660                         $allowOrigin = '*';
 661                         $allowCredentials = 'false';
 662                         $varyOrigin = false; // No need to vary
 663                 } else {
 664                         // Non-anonymous CORS, check we allow the domain
 665
 666                         // Origin: header is a space-separated list of origins, check all of them
 667                         $originHeader = $request->getHeader( 'Origin' );
 668                         if ( $originHeader === false ) {
 669                                 $origins = [];
 670                         } else {
 671                                 $originHeader = trim( $originHeader );
 672                                 $origins = preg_split( '/\s+/', $originHeader );
 673                         }
 674
 675                         if ( !in_array( $originParam, $origins ) ) {
 676                                 // origin parameter set but incorrect
 677                                 // Send a 403 response
 678                                 $response->statusHeader( 403 );
 679                                 $response->header( 'Cache-Control: no-cache' );
 680                                 echo "'origin' parameter does not match Origin header\n";
 681
 682                                 return false;
 683                         }
 684
 685                         $config = $this->getConfig();
 686                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 687                                 $originParam,
 688                                 $config->get( 'CrossSiteAJAXdomains' ),
 689                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 690                         );
 691
 692                         $allowOrigin = $originHeader;
 693                         $allowCredentials = 'true';
 694                         $allowTiming = $originHeader;
 695                 }
 696
 697                 if ( $matchOrigin ) {
 698                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 699                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 700                         if ( $preflight ) {
 701                                 // This is a CORS preflight request
 702                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 703                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 704                                         return true;
 705                                 }
 706                                 // We allow the actual request to send the following headers
 707                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 708                                 if ( $requestedHeaders !== false ) {
 709                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 710                                                 return true;
 711                                         }
 712                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 713                                 }
 714
 715                                 // We only allow the actual request to be GET or POST
 716                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 717                         }
 718
 719                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 720                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 721                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 722                         if ( $allowTiming !== false ) {
 723                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 724                         }
 725
 726                         if ( !$preflight ) {
 727                                 $response->header(
 728                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 729                                 );
 730                         }
 731                 }
 732
 733                 if ( $varyOrigin ) {
 734                         $this->getOutput()->addVaryHeader( 'Origin' );
 735                 }
 736
 737                 return true;
 738         }
 739
 740         /**
 741          * Attempt to match an Origin header against a set of rules and a set of exceptions
 742          * @param string $value Origin header
 743          * @param array $rules Set of wildcard rules
 744          * @param array $exceptions Set of wildcard rules
 745          * @return bool True if $value matches a rule in $rules and doesn't match
 746          *    any rules in $exceptions, false otherwise
 747          */
 748         protected static function matchOrigin( $value, $rules, $exceptions ) {
 749                 foreach ( $rules as $rule ) {
 750                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 751                                 // Rule matches, check exceptions
 752                                 foreach ( $exceptions as $exc ) {
 753                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 754                                                 return false;
 755                                         }
 756                                 }
 757
 758                                 return true;
 759                         }
 760                 }
 761
 762                 return false;
 763         }
 764
 765         /**
 766          * Attempt to validate the value of Access-Control-Request-Headers against a list
 767          * of headers that we allow the follow up request to send.
 768          *
 769          * @param string $requestedHeaders Comma seperated list of HTTP headers
 770          * @return bool True if all requested headers are in the list of allowed headers
 771          */
 772         protected static function matchRequestedHeaders( $requestedHeaders ) {
 773                 if ( trim( $requestedHeaders ) === '' ) {
 774                         return true;
 775                 }
 776                 $requestedHeaders = explode( ',', $requestedHeaders );
 777                 $allowedAuthorHeaders = array_flip( [
 778                         /* simple headers (see spec) */
 779                         'accept',
 780                         'accept-language',
 781                         'content-language',
 782                         'content-type',
 783                         /* non-authorable headers in XHR, which are however requested by some UAs */
 784                         'accept-encoding',
 785                         'dnt',
 786                         'origin',
 787                         /* MediaWiki whitelist */
 788                         'api-user-agent',
 789                 ] );
 790                 foreach ( $requestedHeaders as $rHeader ) {
 791                         $rHeader = strtolower( trim( $rHeader ) );
 792                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 793                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 794                                 return false;
 795                         }
 796                 }
 797                 return true;
 798         }
 799
 800         /**
 801          * Helper function to convert wildcard string into a regex
 802          * '*' => '.*?'
 803          * '?' => '.'
 804          *
 805          * @param string $wildcard String with wildcards
 806          * @return string Regular expression
 807          */
 808         protected static function wildcardToRegex( $wildcard ) {
 809                 $wildcard = preg_quote( $wildcard, '/' );
 810                 $wildcard = str_replace(
 811                         [ '\*', '\?' ],
 812                         [ '.*?', '.' ],
 813                         $wildcard
 814                 );
 815
 816                 return "/^https?:\/\/$wildcard$/";
 817         }
 818
 819         /**
 820          * Send caching headers
 821          * @param bool $isError Whether an error response is being output
 822          * @since 1.26 added $isError parameter
 823          */
 824         protected function sendCacheHeaders( $isError ) {
 825                 $response = $this->getRequest()->response();
 826                 $out = $this->getOutput();
 827
 828                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 829
 830                 $config = $this->getConfig();
 831
 832                 if ( $config->get( 'VaryOnXFP' ) ) {
 833                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 834                 }
 835
 836                 if ( !$isError && $this->mModule &&
 837                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 838                 ) {
 839                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 840                         if ( $etag !== null ) {
 841                                 $response->header( "ETag: $etag" );
 842                         }
 843                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 844                         if ( $lastMod !== null ) {
 845                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 846                         }
 847                 }
 848
 849                 // The logic should be:
 850                 // $this->mCacheControl['max-age'] is set?
 851                 //    Use it, the module knows better than our guess.
 852                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 853                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 854                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 855                 $maxage = 0;
 856                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 857                         $maxage = $this->mCacheControl['max-age'];
 858                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 859                         $this->mCacheMode !== 'private'
 860                 ) {
 861                         $maxage = $this->getParameter( 'maxage' );
 862                 }
 863                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 864
 865                 if ( $this->mCacheMode == 'private' ) {
 866                         $response->header( "Cache-Control: $privateCache" );
 867                         return;
 868                 }
 869
 870                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 871                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 872                         $out->addVaryHeader( 'Cookie' );
 873                         $response->header( $out->getVaryHeader() );
 874                         if ( $useKeyHeader ) {
 875                                 $response->header( $out->getKeyHeader() );
 876                                 if ( $out->haveCacheVaryCookies() ) {
 877                                         // Logged in, mark this request private
 878                                         $response->header( "Cache-Control: $privateCache" );
 879                                         return;
 880                                 }
 881                                 // Logged out, send normal public headers below
 882                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 883                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 884                                 // Mark request private
 885                                 $response->header( "Cache-Control: $privateCache" );
 886
 887                                 return;
 888                         } // else no Key and anonymous, send public headers below
 889                 }
 890
 891                 // Send public headers
 892                 $response->header( $out->getVaryHeader() );
 893                 if ( $useKeyHeader ) {
 894                         $response->header( $out->getKeyHeader() );
 895                 }
 896
 897                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 898                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 899                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 900                 }
 901                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 902                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 903                 }
 904
 905                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 906                         // Public cache not requested
 907                         // Sending a Vary header in this case is harmless, and protects us
 908                         // against conditional calls of setCacheMaxAge().
 909                         $response->header( "Cache-Control: $privateCache" );
 910
 911                         return;
 912                 }
 913
 914                 $this->mCacheControl['public'] = true;
 915
 916                 // Send an Expires header
 917                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 918                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 919                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 920
 921                 // Construct the Cache-Control header
 922                 $ccHeader = '';
 923                 $separator = '';
 924                 foreach ( $this->mCacheControl as $name => $value ) {
 925                         if ( is_bool( $value ) ) {
 926                                 if ( $value ) {
 927                                         $ccHeader .= $separator . $name;
 928                                         $separator = ', ';
 929                                 }
 930                         } else {
 931                                 $ccHeader .= $separator . "$name=$value";
 932                                 $separator = ', ';
 933                         }
 934                 }
 935
 936                 $response->header( "Cache-Control: $ccHeader" );
 937         }
 938
 939         /**
 940          * Create the printer for error output
 941          */
 942         private function createErrorPrinter() {
 943                 if ( !isset( $this->mPrinter ) ) {
 944                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 945                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 946                                 $value = self::API_DEFAULT_FORMAT;
 947                         }
 948                         $this->mPrinter = $this->createPrinterByName( $value );
 949                 }
 950
 951                 // Printer may not be able to handle errors. This is particularly
 952                 // likely if the module returns something for getCustomPrinter().
 953                 if ( !$this->mPrinter->canPrintErrors() ) {
 954                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 955                 }
 956         }
 957
 958         /**
 959          * Create an error message for the given exception.
 960          *
 961          * If the exception is a UsageException then
 962          * UsageException::getMessageArray() will be called to create the message.
 963          *
 964          * @param Exception $e
 965          * @return array ['code' => 'some string', 'info' => 'some other string']
 966          * @since 1.27
 967          */
 968         protected function errorMessageFromException( $e ) {
 969                 if ( $e instanceof UsageException ) {
 970                         // User entered incorrect parameters - generate error response
 971                         $errMessage = $e->getMessageArray();
 972                 } else {
 973                         $config = $this->getConfig();
 974                         // Something is seriously wrong
 975                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 976                                 $info = 'Database query error';
 977                         } else {
 978                                 $info = "Exception Caught: {$e->getMessage()}";
 979                         }
 980
 981                         $errMessage = [
 982                                 'code' => 'internal_api_error_' . get_class( $e ),
 983                                 'info' => '[' . WebRequest::getRequestId() . '] ' . $info,
 984                         ];
 985                 }
 986                 return $errMessage;
 987         }
 988
 989         /**
 990          * Replace the result data with the information about an exception.
 991          * Returns the error code
 992          * @param Exception $e
 993          * @return string
 994          */
 995         protected function substituteResultWithError( $e ) {
 996                 $result = $this->getResult();
 997                 $config = $this->getConfig();
 998
 999                 $errMessage = $this->errorMessageFromException( $e );
1000                 if ( $e instanceof UsageException ) {
1001                         // User entered incorrect parameters - generate error response
1002                         $link = wfExpandUrl( wfScript( 'api' ) );
1003                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
1004                 } else {
1005                         // Something is seriously wrong
1006                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1007                                 ApiResult::setContentValue(
1008                                         $errMessage,
1009                                         'trace',
1010                                         MWExceptionHandler::getRedactedTraceAsString( $e )
1011                                 );
1012                         }
1013                 }
1014
1015                 // Remember all the warnings to re-add them later
1016                 $warnings = $result->getResultData( [ 'warnings' ] );
1017
1018                 $result->reset();
1019                 // Re-add the id
1020                 $requestid = $this->getParameter( 'requestid' );
1021                 if ( !is_null( $requestid ) ) {
1022                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1023                 }
1024                 if ( $config->get( 'ShowHostnames' ) ) {
1025                         // servedby is especially useful when debugging errors
1026                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1027                 }
1028                 if ( $warnings !== null ) {
1029                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1030                 }
1031
1032                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
1033
1034                 return $errMessage['code'];
1035         }
1036
1037         /**
1038          * Set up for the execution.
1039          * @return array
1040          */
1041         protected function setupExecuteAction() {
1042                 // First add the id to the top element
1043                 $result = $this->getResult();
1044                 $requestid = $this->getParameter( 'requestid' );
1045                 if ( !is_null( $requestid ) ) {
1046                         $result->addValue( null, 'requestid', $requestid );
1047                 }
1048
1049                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1050                         $servedby = $this->getParameter( 'servedby' );
1051                         if ( $servedby ) {
1052                                 $result->addValue( null, 'servedby', wfHostname() );
1053                         }
1054                 }
1055
1056                 if ( $this->getParameter( 'curtimestamp' ) ) {
1057                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1058                                 ApiResult::NO_SIZE_CHECK );
1059                 }
1060
1061                 $params = $this->extractRequestParams();
1062
1063                 $this->mAction = $params['action'];
1064
1065                 if ( !is_string( $this->mAction ) ) {
1066                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1067                 }
1068
1069                 return $params;
1070         }
1071
1072         /**
1073          * Set up the module for response
1074          * @return ApiBase The module that will handle this action
1075          * @throws MWException
1076          * @throws UsageException
1077          */
1078         protected function setupModule() {
1079                 // Instantiate the module requested by the user
1080                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1081                 if ( $module === null ) {
1082                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1083                 }
1084                 $moduleParams = $module->extractRequestParams();
1085
1086                 // Check token, if necessary
1087                 if ( $module->needsToken() === true ) {
1088                         throw new MWException(
1089                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1090                                 'See documentation for ApiBase::needsToken for details.'
1091                         );
1092                 }
1093                 if ( $module->needsToken() ) {
1094                         if ( !$module->mustBePosted() ) {
1095                                 throw new MWException(
1096                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1097                                 );
1098                         }
1099
1100                         if ( !isset( $moduleParams['token'] ) ) {
1101                                 $this->dieUsageMsg( [ 'missingparam', 'token' ] );
1102                         }
1103
1104                         if ( !$this->getConfig()->get( 'DebugAPI' ) &&
1105                                 array_key_exists(
1106                                         $module->encodeParamName( 'token' ),
1107                                         $this->getRequest()->getQueryValues()
1108                                 )
1109                         ) {
1110                                 $this->dieUsage(
1111                                         "The '{$module->encodeParamName( 'token' )}' parameter was " .
1112                                                 'found in the query string, but must be in the POST body',
1113                                         'mustposttoken'
1114                                 );
1115                         }
1116
1117                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1118                                 $this->dieUsageMsg( 'sessionfailure' );
1119                         }
1120                 }
1121
1122                 return $module;
1123         }
1124
1125         /**
1126          * Check the max lag if necessary
1127          * @param ApiBase $module Api module being used
1128          * @param array $params Array an array containing the request parameters.
1129          * @return bool True on success, false should exit immediately
1130          */
1131         protected function checkMaxLag( $module, $params ) {
1132                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1133                         $maxLag = $params['maxlag'];
1134                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1135                         if ( $lag > $maxLag ) {
1136                                 $response = $this->getRequest()->response();
1137
1138                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1139                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1140
1141                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1142                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1143                                 }
1144
1145                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1146                         }
1147                 }
1148
1149                 return true;
1150         }
1151
1152         /**
1153          * Check selected RFC 7232 precondition headers
1154          *
1155          * RFC 7232 envisions a particular model where you send your request to "a
1156          * resource", and for write requests that you can read "the resource" by
1157          * changing the method to GET. When the API receives a GET request, it
1158          * works out even though "the resource" from RFC 7232's perspective might
1159          * be many resources from MediaWiki's perspective. But it totally fails for
1160          * a POST, since what HTTP sees as "the resource" is probably just
1161          * "/api.php" with all the interesting bits in the body.
1162          *
1163          * Therefore, we only support RFC 7232 precondition headers for GET (and
1164          * HEAD). That means we don't need to bother with If-Match and
1165          * If-Unmodified-Since since they only apply to modification requests.
1166          *
1167          * And since we don't support Range, If-Range is ignored too.
1168          *
1169          * @since 1.26
1170          * @param ApiBase $module Api module being used
1171          * @return bool True on success, false should exit immediately
1172          */
1173         protected function checkConditionalRequestHeaders( $module ) {
1174                 if ( $this->mInternalMode ) {
1175                         // No headers to check in internal mode
1176                         return true;
1177                 }
1178
1179                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1180                         // Don't check POSTs
1181                         return true;
1182                 }
1183
1184                 $return304 = false;
1185
1186                 $ifNoneMatch = array_diff(
1187                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1188                         [ '' ]
1189                 );
1190                 if ( $ifNoneMatch ) {
1191                         if ( $ifNoneMatch === [ '*' ] ) {
1192                                 // API responses always "exist"
1193                                 $etag = '*';
1194                         } else {
1195                                 $etag = $module->getConditionalRequestData( 'etag' );
1196                         }
1197                 }
1198                 if ( $ifNoneMatch && $etag !== null ) {
1199                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1200                         $match = array_map( function ( $s ) {
1201                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1202                         }, $ifNoneMatch );
1203                         $return304 = in_array( $test, $match, true );
1204                 } else {
1205                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1206
1207                         // Some old browsers sends sizes after the date, like this:
1208                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1209                         // Ignore that.
1210                         $i = strpos( $value, ';' );
1211                         if ( $i !== false ) {
1212                                 $value = trim( substr( $value, 0, $i ) );
1213                         }
1214
1215                         if ( $value !== '' ) {
1216                                 try {
1217                                         $ts = new MWTimestamp( $value );
1218                                         if (
1219                                                 // RFC 7231 IMF-fixdate
1220                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1221                                                 // RFC 850
1222                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1223                                                 // asctime (with and without space-padded day)
1224                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1225                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1226                                         ) {
1227                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1228                                                 if ( $lastMod !== null ) {
1229                                                         // Mix in some MediaWiki modification times
1230                                                         $modifiedTimes = [
1231                                                                 'page' => $lastMod,
1232                                                                 'user' => $this->getUser()->getTouched(),
1233                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1234                                                         ];
1235                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1236                                                                 // T46570: the core page itself may not change, but resources might
1237                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1238                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1239                                                                 );
1240                                                         }
1241                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1242                                                         $lastMod = max( $modifiedTimes );
1243                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1244                                                 }
1245                                         }
1246                                 } catch ( TimestampException $e ) {
1247                                         // Invalid timestamp, ignore it
1248                                 }
1249                         }
1250                 }
1251
1252                 if ( $return304 ) {
1253                         $this->getRequest()->response()->statusHeader( 304 );
1254
1255                         // Avoid outputting the compressed representation of a zero-length body
1256                         MediaWiki\suppressWarnings();
1257                         ini_set( 'zlib.output_compression', 0 );
1258                         MediaWiki\restoreWarnings();
1259                         wfClearOutputBuffers();
1260
1261                         return false;
1262                 }
1263
1264                 return true;
1265         }
1266
1267         /**
1268          * Check for sufficient permissions to execute
1269          * @param ApiBase $module An Api module
1270          */
1271         protected function checkExecutePermissions( $module ) {
1272                 $user = $this->getUser();
1273                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1274                         !$user->isAllowed( 'read' )
1275                 ) {
1276                         $this->dieUsageMsg( 'readrequired' );
1277                 }
1278
1279                 if ( $module->isWriteMode() ) {
1280                         if ( !$this->mEnableWrite ) {
1281                                 $this->dieUsageMsg( 'writedisabled' );
1282                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1283                                 $this->dieUsageMsg( 'writerequired' );
1284                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1285                                 $this->dieUsage(
1286                                         'Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules',
1287                                         'promised-nonwrite-api'
1288                                 );
1289                         }
1290
1291                         $this->checkReadOnly( $module );
1292                 }
1293
1294                 // Allow extensions to stop execution for arbitrary reasons.
1295                 $message = false;
1296                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1297                         $this->dieUsageMsg( $message );
1298                 }
1299         }
1300
1301         /**
1302          * Check if the DB is read-only for this user
1303          * @param ApiBase $module An Api module
1304          */
1305         protected function checkReadOnly( $module ) {
1306                 if ( wfReadOnly() ) {
1307                         $this->dieReadOnly();
1308                 }
1309
1310                 if ( $module->isWriteMode()
1311                         && in_array( 'bot', $this->getUser()->getGroups() )
1312                         && wfGetLB()->getServerCount() > 1
1313                 ) {
1314                         $this->checkBotReadOnly();
1315                 }
1316         }
1317
1318         /**
1319          * Check whether we are readonly for bots
1320          */
1321         private function checkBotReadOnly() {
1322                 // Figure out how many servers have passed the lag threshold
1323                 $numLagged = 0;
1324                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1325                 $laggedServers = [];
1326                 $loadBalancer = wfGetLB();
1327                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1328                         if ( $lag > $lagLimit ) {
1329                                 ++$numLagged;
1330                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1331                         }
1332                 }
1333
1334                 // If a majority of slaves are too lagged then disallow writes
1335                 $slaveCount = wfGetLB()->getServerCount() - 1;
1336                 if ( $numLagged >= ceil( $slaveCount / 2 ) ) {
1337                         $laggedServers = implode( ', ', $laggedServers );
1338                         wfDebugLog(
1339                                 'api-readonly',
1340                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1341                         );
1342
1343                         $parsed = $this->parseMsg( [ 'readonlytext' ] );
1344                         $this->dieUsage(
1345                                 $parsed['info'],
1346                                 $parsed['code'],
1347                                 /* http error */
1348                                 0,
1349                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1350                         );
1351                 }
1352         }
1353
1354         /**
1355          * Check asserts of the user's rights
1356          * @param array $params
1357          */
1358         protected function checkAsserts( $params ) {
1359                 if ( isset( $params['assert'] ) ) {
1360                         $user = $this->getUser();
1361                         switch ( $params['assert'] ) {
1362                                 case 'user':
1363                                         if ( $user->isAnon() ) {
1364                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1365                                         }
1366                                         break;
1367                                 case 'bot':
1368                                         if ( !$user->isAllowed( 'bot' ) ) {
1369                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1370                                         }
1371                                         break;
1372                         }
1373                 }
1374         }
1375
1376         /**
1377          * Check POST for external response and setup result printer
1378          * @param ApiBase $module An Api module
1379          * @param array $params An array with the request parameters
1380          */
1381         protected function setupExternalResponse( $module, $params ) {
1382                 $request = $this->getRequest();
1383                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1384                         // Module requires POST. GET request might still be allowed
1385                         // if $wgDebugApi is true, otherwise fail.
1386                         $this->dieUsageMsgOrDebug( [ 'mustbeposted', $this->mAction ] );
1387                 }
1388
1389                 // See if custom printer is used
1390                 $this->mPrinter = $module->getCustomPrinter();
1391                 if ( is_null( $this->mPrinter ) ) {
1392                         // Create an appropriate printer
1393                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1394                 }
1395
1396                 if ( $request->getProtocol() === 'http' && (
1397                         $request->getSession()->shouldForceHTTPS() ||
1398                         ( $this->getUser()->isLoggedIn() &&
1399                                 $this->getUser()->requiresHTTPS() )
1400                 ) ) {
1401                         $this->logFeatureUsage( 'https-expected' );
1402                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1403                 }
1404         }
1405
1406         /**
1407          * Execute the actual module, without any error handling
1408          */
1409         protected function executeAction() {
1410                 $params = $this->setupExecuteAction();
1411                 $module = $this->setupModule();
1412                 $this->mModule = $module;
1413
1414                 if ( !$this->mInternalMode ) {
1415                         $this->setRequestExpectations( $module );
1416                 }
1417
1418                 $this->checkExecutePermissions( $module );
1419
1420                 if ( !$this->checkMaxLag( $module, $params ) ) {
1421                         return;
1422                 }
1423
1424                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1425                         return;
1426                 }
1427
1428                 if ( !$this->mInternalMode ) {
1429                         $this->setupExternalResponse( $module, $params );
1430                 }
1431
1432                 $this->checkAsserts( $params );
1433
1434                 // Execute
1435                 $module->execute();
1436                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1437
1438                 $this->reportUnusedParams();
1439
1440                 if ( !$this->mInternalMode ) {
1441                         // append Debug information
1442                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1443
1444                         // Print result data
1445                         $this->printResult( false );
1446                 }
1447         }
1448
1449         /**
1450          * Set database connection, query, and write expectations given this module request
1451          * @param ApiBase $module
1452          */
1453         protected function setRequestExpectations( ApiBase $module ) {
1454                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1455                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1456                 if ( $this->getRequest()->hasSafeMethod() ) {
1457                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1458                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1459                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1460                         $this->getRequest()->markAsSafeRequest();
1461                 } else {
1462                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1463                 }
1464         }
1465
1466         /**
1467          * Log the preceding request
1468          * @param float $time Time in seconds
1469          * @param Exception $e Exception caught while processing the request
1470          */
1471         protected function logRequest( $time, $e = null ) {
1472                 $request = $this->getRequest();
1473                 $logCtx = [
1474                         'ts' => time(),
1475                         'ip' => $request->getIP(),
1476                         'userAgent' => $this->getUserAgent(),
1477                         'wiki' => wfWikiID(),
1478                         'timeSpentBackend' => (int) round( $time * 1000 ),
1479                         'hadError' => $e !== null,
1480                         'errorCodes' => [],
1481                         'params' => [],
1482                 ];
1483
1484                 if ( $e ) {
1485                         $logCtx['errorCodes'][] = $this->errorMessageFromException( $e )['code'];
1486                 }
1487
1488                 // Construct space separated message for 'api' log channel
1489                 $msg = "API {$request->getMethod()} " .
1490                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1491                         " {$logCtx['ip']} " .
1492                         "T={$logCtx['timeSpentBackend']}ms";
1493
1494                 foreach ( $this->getParamsUsed() as $name ) {
1495                         $value = $request->getVal( $name );
1496                         if ( $value === null ) {
1497                                 continue;
1498                         }
1499
1500                         if ( strlen( $value ) > 256 ) {
1501                                 $value = substr( $value, 0, 256 );
1502                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1503                         } else {
1504                                 $encValue = $this->encodeRequestLogValue( $value );
1505                         }
1506
1507                         $logCtx['params'][$name] = $value;
1508                         $msg .= " {$name}={$encValue}";
1509                 }
1510
1511                 wfDebugLog( 'api', $msg, 'private' );
1512                 // ApiAction channel is for structured data consumers
1513                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1514         }
1515
1516         /**
1517          * Encode a value in a format suitable for a space-separated log line.
1518          * @param string $s
1519          * @return string
1520          */
1521         protected function encodeRequestLogValue( $s ) {
1522                 static $table;
1523                 if ( !$table ) {
1524                         $chars = ';@$!*(),/:';
1525                         $numChars = strlen( $chars );
1526                         for ( $i = 0; $i < $numChars; $i++ ) {
1527                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1528                         }
1529                 }
1530
1531                 return strtr( rawurlencode( $s ), $table );
1532         }
1533
1534         /**
1535          * Get the request parameters used in the course of the preceding execute() request
1536          * @return array
1537          */
1538         protected function getParamsUsed() {
1539                 return array_keys( $this->mParamsUsed );
1540         }
1541
1542         /**
1543          * Mark parameters as used
1544          * @param string|string[] $params
1545          */
1546         public function markParamsUsed( $params ) {
1547                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1548         }
1549
1550         /**
1551          * Get a request value, and register the fact that it was used, for logging.
1552          * @param string $name
1553          * @param mixed $default
1554          * @return mixed
1555          */
1556         public function getVal( $name, $default = null ) {
1557                 $this->mParamsUsed[$name] = true;
1558
1559                 $ret = $this->getRequest()->getVal( $name );
1560                 if ( $ret === null ) {
1561                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1562                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1563                                 // array.
1564                                 $this->setWarning(
1565                                         "Parameter '$name' uses unsupported PHP array syntax"
1566                                 );
1567                         }
1568                         $ret = $default;
1569                 }
1570                 return $ret;
1571         }
1572
1573         /**
1574          * Get a boolean request value, and register the fact that the parameter
1575          * was used, for logging.
1576          * @param string $name
1577          * @return bool
1578          */
1579         public function getCheck( $name ) {
1580                 return $this->getVal( $name, null ) !== null;
1581         }
1582
1583         /**
1584          * Get a request upload, and register the fact that it was used, for logging.
1585          *
1586          * @since 1.21
1587          * @param string $name Parameter name
1588          * @return WebRequestUpload
1589          */
1590         public function getUpload( $name ) {
1591                 $this->mParamsUsed[$name] = true;
1592
1593                 return $this->getRequest()->getUpload( $name );
1594         }
1595
1596         /**
1597          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1598          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1599          */
1600         protected function reportUnusedParams() {
1601                 $paramsUsed = $this->getParamsUsed();
1602                 $allParams = $this->getRequest()->getValueNames();
1603
1604                 if ( !$this->mInternalMode ) {
1605                         // Printer has not yet executed; don't warn that its parameters are unused
1606                         $printerParams = array_map(
1607                                 [ $this->mPrinter, 'encodeParamName' ],
1608                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1609                         );
1610                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1611                 } else {
1612                         $unusedParams = array_diff( $allParams, $paramsUsed );
1613                 }
1614
1615                 if ( count( $unusedParams ) ) {
1616                         $s = count( $unusedParams ) > 1 ? 's' : '';
1617                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1618                 }
1619         }
1620
1621         /**
1622          * Print results using the current printer
1623          *
1624          * @param bool $isError
1625          */
1626         protected function printResult( $isError ) {
1627                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1628                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1629                 }
1630
1631                 $printer = $this->mPrinter;
1632                 $printer->initPrinter( false );
1633                 $printer->execute();
1634                 $printer->closePrinter();
1635         }
1636
1637         /**
1638          * @return bool
1639          */
1640         public function isReadMode() {
1641                 return false;
1642         }
1643
1644         /**
1645          * See ApiBase for description.
1646          *
1647          * @return array
1648          */
1649         public function getAllowedParams() {
1650                 return [
1651                         'action' => [
1652                                 ApiBase::PARAM_DFLT => 'help',
1653                                 ApiBase::PARAM_TYPE => 'submodule',
1654                         ],
1655                         'format' => [
1656                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1657                                 ApiBase::PARAM_TYPE => 'submodule',
1658                         ],
1659                         'maxlag' => [
1660                                 ApiBase::PARAM_TYPE => 'integer'
1661                         ],
1662                         'smaxage' => [
1663                                 ApiBase::PARAM_TYPE => 'integer',
1664                                 ApiBase::PARAM_DFLT => 0
1665                         ],
1666                         'maxage' => [
1667                                 ApiBase::PARAM_TYPE => 'integer',
1668                                 ApiBase::PARAM_DFLT => 0
1669                         ],
1670                         'assert' => [
1671                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1672                         ],
1673                         'requestid' => null,
1674                         'servedby' => false,
1675                         'curtimestamp' => false,
1676                         'origin' => null,
1677                         'uselang' => [
1678                                 ApiBase::PARAM_DFLT => 'user',
1679                         ],
1680                 ];
1681         }
1682
1683         /** @see ApiBase::getExamplesMessages() */
1684         protected function getExamplesMessages() {
1685                 return [
1686                         'action=help'
1687                                 => 'apihelp-help-example-main',
1688                         'action=help&recursivesubmodules=1'
1689                                 => 'apihelp-help-example-recursive',
1690                 ];
1691         }
1692
1693         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1694                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1695                 // reindex the array to get 'permissions' in the right place.
1696                 $oldHelp = $help;
1697                 $help = [];
1698                 foreach ( $oldHelp as $k => $v ) {
1699                         if ( $k === 'submodules' ) {
1700                                 $help['permissions'] = '';
1701                         }
1702                         $help[$k] = $v;
1703                 }
1704                 $help['datatypes'] = '';
1705                 $help['credits'] = '';
1706
1707                 // Fill 'permissions'
1708                 $help['permissions'] .= Html::openElement( 'div',
1709                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1710                 $m = $this->msg( 'api-help-permissions' );
1711                 if ( !$m->isDisabled() ) {
1712                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1713                                 $m->numParams( count( self::$mRights ) )->parse()
1714                         );
1715                 }
1716                 $help['permissions'] .= Html::openElement( 'dl' );
1717                 foreach ( self::$mRights as $right => $rightMsg ) {
1718                         $help['permissions'] .= Html::element( 'dt', null, $right );
1719
1720                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1721                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1722
1723                         $groups = array_map( function ( $group ) {
1724                                 return $group == '*' ? 'all' : $group;
1725                         }, User::getGroupsWithPermission( $right ) );
1726
1727                         $help['permissions'] .= Html::rawElement( 'dd', null,
1728                                 $this->msg( 'api-help-permissions-granted-to' )
1729                                         ->numParams( count( $groups ) )
1730                                         ->params( $this->getLanguage()->commaList( $groups ) )
1731                                         ->parse()
1732                         );
1733                 }
1734                 $help['permissions'] .= Html::closeElement( 'dl' );
1735                 $help['permissions'] .= Html::closeElement( 'div' );
1736
1737                 // Fill 'datatypes' and 'credits', if applicable
1738                 if ( empty( $options['nolead'] ) ) {
1739                         $level = $options['headerlevel'];
1740                         $tocnumber = &$options['tocnumber'];
1741
1742                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1743
1744                         // Add an additional span with sanitized ID
1745                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1746                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1747                                         $header;
1748                         }
1749                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1750                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1751                                 $header
1752                         );
1753                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1754                         if ( !isset( $tocData['main/datatypes'] ) ) {
1755                                 $tocnumber[$level]++;
1756                                 $tocData['main/datatypes'] = [
1757                                         'toclevel' => count( $tocnumber ),
1758                                         'level' => $level,
1759                                         'anchor' => 'main/datatypes',
1760                                         'line' => $header,
1761                                         'number' => implode( '.', $tocnumber ),
1762                                         'index' => false,
1763                                 ];
1764                         }
1765
1766                         // Add an additional span with sanitized ID
1767                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1768                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1769                                         $header;
1770                         }
1771                         $header = $this->msg( 'api-credits-header' )->parse();
1772                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1773                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1774                                 $header
1775                         );
1776                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1777                         if ( !isset( $tocData['main/credits'] ) ) {
1778                                 $tocnumber[$level]++;
1779                                 $tocData['main/credits'] = [
1780                                         'toclevel' => count( $tocnumber ),
1781                                         'level' => $level,
1782                                         'anchor' => 'main/credits',
1783                                         'line' => $header,
1784                                         'number' => implode( '.', $tocnumber ),
1785                                         'index' => false,
1786                                 ];
1787                         }
1788                 }
1789         }
1790
1791         private $mCanApiHighLimits = null;
1792
1793         /**
1794          * Check whether the current user is allowed to use high limits
1795          * @return bool
1796          */
1797         public function canApiHighLimits() {
1798                 if ( !isset( $this->mCanApiHighLimits ) ) {
1799                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1800                 }
1801
1802                 return $this->mCanApiHighLimits;
1803         }
1804
1805         /**
1806          * Overrides to return this instance's module manager.
1807          * @return ApiModuleManager
1808          */
1809         public function getModuleManager() {
1810                 return $this->mModuleMgr;
1811         }
1812
1813         /**
1814          * Fetches the user agent used for this request
1815          *
1816          * The value will be the combination of the 'Api-User-Agent' header (if
1817          * any) and the standard User-Agent header (if any).
1818          *
1819          * @return string
1820          */
1821         public function getUserAgent() {
1822                 return trim(
1823                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1824                         $this->getRequest()->getHeader( 'User-agent' )
1825                 );
1826         }
1827
1828         /************************************************************************//**
1829          * @name   Deprecated
1830          * @{
1831          */
1832
1833         /**
1834          * Sets whether the pretty-printer should format *bold* and $italics$
1835          *
1836          * @deprecated since 1.25
1837          * @param bool $help
1838          */
1839         public function setHelp( $help = true ) {
1840                 wfDeprecated( __METHOD__, '1.25' );
1841                 $this->mPrinter->setHelp( $help );
1842         }
1843
1844         /**
1845          * Override the parent to generate help messages for all available modules.
1846          *
1847          * @deprecated since 1.25
1848          * @return string
1849          */
1850         public function makeHelpMsg() {
1851                 wfDeprecated( __METHOD__, '1.25' );
1852
1853                 $this->setHelp();
1854                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1855
1856                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1857                         wfMemcKey(
1858                                 'apihelp',
1859                                 $this->getModuleName(),
1860                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1861                         ),
1862                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1863                         [ $this, 'reallyMakeHelpMsg' ]
1864                 );
1865         }
1866
1867         /**
1868          * @deprecated since 1.25
1869          * @return mixed|string
1870          */
1871         public function reallyMakeHelpMsg() {
1872                 wfDeprecated( __METHOD__, '1.25' );
1873                 $this->setHelp();
1874
1875                 // Use parent to make default message for the main module
1876                 $msg = parent::makeHelpMsg();
1877
1878                 $asterisks = str_repeat( '*** ', 14 );
1879                 $msg .= "\n\n$asterisks Modules  $asterisks\n\n";
1880
1881                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1882                         $module = $this->mModuleMgr->getModule( $name );
1883                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1884
1885                         $msg2 = $module->makeHelpMsg();
1886                         if ( $msg2 !== false ) {
1887                                 $msg .= $msg2;
1888                         }
1889                         $msg .= "\n";
1890                 }
1891
1892                 $msg .= "\n$asterisks Permissions $asterisks\n\n";
1893                 foreach ( self::$mRights as $right => $rightMsg ) {
1894                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1895                                 ->useDatabase( false )
1896                                 ->inLanguage( 'en' )
1897                                 ->text();
1898                         $groups = User::getGroupsWithPermission( $right );
1899                         $msg .= '* ' . $right . " *\n  $rightsMsg" .
1900                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1901                 }
1902
1903                 $msg .= "\n$asterisks Formats  $asterisks\n\n";
1904                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1905                         $module = $this->mModuleMgr->getModule( $name );
1906                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1907                         $msg2 = $module->makeHelpMsg();
1908                         if ( $msg2 !== false ) {
1909                                 $msg .= $msg2;
1910                         }
1911                         $msg .= "\n";
1912                 }
1913
1914                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1915                 $credits = str_replace( "\n", "\n   ", $credits );
1916                 $msg .= "\n*** Credits: ***\n   $credits\n";
1917
1918                 return $msg;
1919         }
1920
1921         /**
1922          * @deprecated since 1.25
1923          * @param ApiBase $module
1924          * @param string $paramName What type of request is this? e.g. action,
1925          *    query, list, prop, meta, format
1926          * @return string
1927          */
1928         public static function makeHelpMsgHeader( $module, $paramName ) {
1929                 wfDeprecated( __METHOD__, '1.25' );
1930                 $modulePrefix = $module->getModulePrefix();
1931                 if ( strval( $modulePrefix ) !== '' ) {
1932                         $modulePrefix = "($modulePrefix) ";
1933                 }
1934
1935                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1936         }
1937
1938         /**@}*/
1939
1940 }
1941
1942 /**
1943  * This exception will be thrown when dieUsage is called to stop module execution.
1944  *
1945  * @ingroup API
1946  */
1947 class UsageException extends MWException {
1948
1949         private $mCodestr;
1950
1951         /**
1952          * @var null|array
1953          */
1954         private $mExtraData;
1955
1956         /**
1957          * @param string $message
1958          * @param string $codestr
1959          * @param int $code
1960          * @param array|null $extradata
1961          */
1962         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1963                 parent::__construct( $message, $code );
1964                 $this->mCodestr = $codestr;
1965                 $this->mExtraData = $extradata;
1966
1967                 // This should never happen, so throw an exception about it that will
1968                 // hopefully get logged with a backtrace (T138585)
1969                 if ( !is_string( $codestr ) || $codestr === '' ) {
1970                         throw new InvalidArgumentException( 'Invalid $codestr, was ' .
1971                                 ( $codestr === '' ? 'empty string' : gettype( $codestr ) )
1972                         );
1973                 }
1974         }
1975
1976         /**
1977          * @return string
1978          */
1979         public function getCodeString() {
1980                 return $this->mCodestr;
1981         }
1982
1983         /**
1984          * @return array
1985          */
1986         public function getMessageArray() {
1987                 $result = [
1988                         'code' => $this->mCodestr,
1989                         'info' => $this->getMessage()
1990                 ];
1991                 if ( is_array( $this->mExtraData ) ) {
1992                         $result = array_merge( $result, $this->mExtraData );
1993                 }
1994
1995                 return $result;
1996         }
1997
1998         /**
1999          * @return string
2000          */
2001         public function __toString() {
2002                 return "{$this->getCodeString()}: {$this->getMessage()}";
2003         }
2004 }
2005
2006 /**
2007  * For really cool vim folding this needs to be at the end:
2008  * vim: foldmarker=@{,@} foldmethod=marker
2009  */