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 use MediaWiki\Logger\LoggerFactory;
  29
  30 /**
  31  * This is the main API class, used for both external and internal processing.
  32  * When executed, it will create the requested formatter object,
  33  * instantiate and execute an object associated with the needed action,
  34  * and use formatter to print results.
  35  * In case of an exception, an error message will be printed using the same formatter.
  36  *
  37  * To use API from another application, run it using FauxRequest object, in which
  38  * case any internal exceptions will not be handled but passed up to the caller.
  39  * After successful execution, use getResult() for the resulting data.
  40  *
  41  * @ingroup API
  42  */
  43 class ApiMain extends ApiBase {
  44         /**
  45          * When no format parameter is given, this format will be used
  46          */
  47         const API_DEFAULT_FORMAT = 'jsonfm';
  48
  49         /**
  50          * List of available modules: action name => module class
  51          */
  52         private static $Modules = [
  53                 'login' => 'ApiLogin',
  54                 'clientlogin' => 'ApiClientLogin',
  55                 'logout' => 'ApiLogout',
  56                 'createaccount' => 'ApiAMCreateAccount',
  57                 'linkaccount' => 'ApiLinkAccount',
  58                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  59                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  60                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  61                 'resetpassword' => 'ApiResetPassword',
  62                 'query' => 'ApiQuery',
  63                 'expandtemplates' => 'ApiExpandTemplates',
  64                 'parse' => 'ApiParse',
  65                 'stashedit' => 'ApiStashEdit',
  66                 'opensearch' => 'ApiOpenSearch',
  67                 'feedcontributions' => 'ApiFeedContributions',
  68                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  69                 'feedwatchlist' => 'ApiFeedWatchlist',
  70                 'help' => 'ApiHelp',
  71                 'paraminfo' => 'ApiParamInfo',
  72                 'rsd' => 'ApiRsd',
  73                 'compare' => 'ApiComparePages',
  74                 'tokens' => 'ApiTokens',
  75                 'checktoken' => 'ApiCheckToken',
  76                 'cspreport' => 'ApiCSPReport',
  77
  78                 // Write modules
  79                 'purge' => 'ApiPurge',
  80                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  81                 'rollback' => 'ApiRollback',
  82                 'delete' => 'ApiDelete',
  83                 'undelete' => 'ApiUndelete',
  84                 'protect' => 'ApiProtect',
  85                 'block' => 'ApiBlock',
  86                 'unblock' => 'ApiUnblock',
  87                 'move' => 'ApiMove',
  88                 'edit' => 'ApiEditPage',
  89                 'upload' => 'ApiUpload',
  90                 'filerevert' => 'ApiFileRevert',
  91                 'emailuser' => 'ApiEmailUser',
  92                 'watch' => 'ApiWatch',
  93                 'patrol' => 'ApiPatrol',
  94                 'import' => 'ApiImport',
  95                 'clearhasmsg' => 'ApiClearHasMsg',
  96                 'userrights' => 'ApiUserrights',
  97                 'options' => 'ApiOptions',
  98                 'imagerotate' => 'ApiImageRotate',
  99                 'revisiondelete' => 'ApiRevisionDelete',
 100                 'managetags' => 'ApiManageTags',
 101                 'tag' => 'ApiTag',
 102                 'mergehistory' => 'ApiMergeHistory',
 103         ];
 104
 105         /**
 106          * List of available formats: format name => format class
 107          */
 108         private static $Formats = [
 109                 'json' => 'ApiFormatJson',
 110                 'jsonfm' => 'ApiFormatJson',
 111                 'php' => 'ApiFormatPhp',
 112                 'phpfm' => 'ApiFormatPhp',
 113                 'xml' => 'ApiFormatXml',
 114                 'xmlfm' => 'ApiFormatXml',
 115                 'rawfm' => 'ApiFormatJson',
 116                 'none' => 'ApiFormatNone',
 117         ];
 118
 119         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 120         /**
 121          * List of user roles that are specifically relevant to the API.
 122          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 123          *                'params' => [ $someVarToSubst ] ],
 124          * ];
 125          */
 126         private static $mRights = [
 127                 'writeapi' => [
 128                         'msg' => 'right-writeapi',
 129                         'params' => []
 130                 ],
 131                 'apihighlimits' => [
 132                         'msg' => 'api-help-right-apihighlimits',
 133                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 134                 ]
 135         ];
 136         // @codingStandardsIgnoreEnd
 137
 138         /**
 139          * @var ApiFormatBase
 140          */
 141         private $mPrinter;
 142
 143         private $mModuleMgr, $mResult, $mErrorFormatter;
 144         /** @var ApiContinuationManager|null */
 145         private $mContinuationManager;
 146         private $mAction;
 147         private $mEnableWrite;
 148         private $mInternalMode, $mSquidMaxage;
 149         /** @var ApiBase */
 150         private $mModule;
 151
 152         private $mCacheMode = 'private';
 153         private $mCacheControl = [];
 154         private $mParamsUsed = [];
 155
 156         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 157         private $lacksSameOriginSecurity = null;
 158
 159         /**
 160          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 161          *
 162          * @param IContextSource|WebRequest $context If this is an instance of
 163          *    FauxRequest, errors are thrown and no printing occurs
 164          * @param bool $enableWrite Should be set to true if the api may modify data
 165          */
 166         public function __construct( $context = null, $enableWrite = false ) {
 167                 if ( $context === null ) {
 168                         $context = RequestContext::getMain();
 169                 } elseif ( $context instanceof WebRequest ) {
 170                         // BC for pre-1.19
 171                         $request = $context;
 172                         $context = RequestContext::getMain();
 173                 }
 174                 // We set a derivative context so we can change stuff later
 175                 $this->setContext( new DerivativeContext( $context ) );
 176
 177                 if ( isset( $request ) ) {
 178                         $this->getContext()->setRequest( $request );
 179                 } else {
 180                         $request = $this->getRequest();
 181                 }
 182
 183                 $this->mInternalMode = ( $request instanceof FauxRequest );
 184
 185                 // Special handling for the main module: $parent === $this
 186                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 187
 188                 $config = $this->getConfig();
 189
 190                 if ( !$this->mInternalMode ) {
 191                         // Log if a request with a non-whitelisted Origin header is seen
 192                         // with session cookies.
 193                         $originHeader = $request->getHeader( 'Origin' );
 194                         if ( $originHeader === false ) {
 195                                 $origins = [];
 196                         } else {
 197                                 $originHeader = trim( $originHeader );
 198                                 $origins = preg_split( '/\s+/', $originHeader );
 199                         }
 200                         $sessionCookies = array_intersect(
 201                                 array_keys( $_COOKIE ),
 202                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 203                         );
 204                         if ( $origins && $sessionCookies && (
 205                                 count( $origins ) !== 1 || !self::matchOrigin(
 206                                         $origins[0],
 207                                         $config->get( 'CrossSiteAJAXdomains' ),
 208                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 209                                 )
 210                         ) ) {
 211                                 LoggerFactory::getInstance( 'cors' )->warning(
 212                                         'Non-whitelisted CORS request with session cookies', [
 213                                                 'origin' => $originHeader,
 214                                                 'cookies' => $sessionCookies,
 215                                                 'ip' => $request->getIP(),
 216                                                 'userAgent' => $this->getUserAgent(),
 217                                                 'wiki' => wfWikiID(),
 218                                         ]
 219                                 );
 220                         }
 221
 222                         // If we're in a mode that breaks the same-origin policy, strip
 223                         // user credentials for security.
 224                         if ( $this->lacksSameOriginSecurity() ) {
 225                                 global $wgUser;
 226                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 227                                 $wgUser = new User();
 228                                 $this->getContext()->setUser( $wgUser );
 229                         }
 230                 }
 231
 232                 $uselang = $this->getParameter( 'uselang' );
 233                 if ( $uselang === 'user' ) {
 234                         // Assume the parent context is going to return the user language
 235                         // for uselang=user (see T85635).
 236                 } else {
 237                         if ( $uselang === 'content' ) {
 238                                 global $wgContLang;
 239                                 $uselang = $wgContLang->getCode();
 240                         }
 241                         $code = RequestContext::sanitizeLangCode( $uselang );
 242                         $this->getContext()->setLanguage( $code );
 243                         if ( !$this->mInternalMode ) {
 244                                 global $wgLang;
 245                                 $wgLang = $this->getContext()->getLanguage();
 246                                 RequestContext::getMain()->setLanguage( $wgLang );
 247                         }
 248                 }
 249
 250                 $this->mModuleMgr = new ApiModuleManager( $this );
 251                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 252                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 253                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 254                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 255
 256                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 257
 258                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 259                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 260                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 261                 $this->mResult->setMainForContinuation( $this );
 262                 $this->mContinuationManager = null;
 263                 $this->mEnableWrite = $enableWrite;
 264
 265                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 266                 $this->mCommit = false;
 267         }
 268
 269         /**
 270          * Return true if the API was started by other PHP code using FauxRequest
 271          * @return bool
 272          */
 273         public function isInternalMode() {
 274                 return $this->mInternalMode;
 275         }
 276
 277         /**
 278          * Get the ApiResult object associated with current request
 279          *
 280          * @return ApiResult
 281          */
 282         public function getResult() {
 283                 return $this->mResult;
 284         }
 285
 286         /**
 287          * Get the security flag for the current request
 288          * @return bool
 289          */
 290         public function lacksSameOriginSecurity() {
 291                 if ( $this->lacksSameOriginSecurity !== null ) {
 292                         return $this->lacksSameOriginSecurity;
 293                 }
 294
 295                 $request = $this->getRequest();
 296
 297                 // JSONP mode
 298                 if ( $request->getVal( 'callback' ) !== null ) {
 299                         $this->lacksSameOriginSecurity = true;
 300                         return true;
 301                 }
 302
 303                 // Anonymous CORS
 304                 if ( $request->getVal( 'origin' ) === '*' ) {
 305                         $this->lacksSameOriginSecurity = true;
 306                         return true;
 307                 }
 308
 309                 // Header to be used from XMLHTTPRequest when the request might
 310                 // otherwise be used for XSS.
 311                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 312                         $this->lacksSameOriginSecurity = true;
 313                         return true;
 314                 }
 315
 316                 // Allow extensions to override.
 317                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 318                 return $this->lacksSameOriginSecurity;
 319         }
 320
 321         /**
 322          * Get the ApiErrorFormatter object associated with current request
 323          * @return ApiErrorFormatter
 324          */
 325         public function getErrorFormatter() {
 326                 return $this->mErrorFormatter;
 327         }
 328
 329         /**
 330          * Get the continuation manager
 331          * @return ApiContinuationManager|null
 332          */
 333         public function getContinuationManager() {
 334                 return $this->mContinuationManager;
 335         }
 336
 337         /**
 338          * Set the continuation manager
 339          * @param ApiContinuationManager|null
 340          */
 341         public function setContinuationManager( $manager ) {
 342                 if ( $manager !== null ) {
 343                         if ( !$manager instanceof ApiContinuationManager ) {
 344                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 345                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 346                                 );
 347                         }
 348                         if ( $this->mContinuationManager !== null ) {
 349                                 throw new UnexpectedValueException(
 350                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 351                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 352                                 );
 353                         }
 354                 }
 355                 $this->mContinuationManager = $manager;
 356         }
 357
 358         /**
 359          * Get the API module object. Only works after executeAction()
 360          *
 361          * @return ApiBase
 362          */
 363         public function getModule() {
 364                 return $this->mModule;
 365         }
 366
 367         /**
 368          * Get the result formatter object. Only works after setupExecuteAction()
 369          *
 370          * @return ApiFormatBase
 371          */
 372         public function getPrinter() {
 373                 return $this->mPrinter;
 374         }
 375
 376         /**
 377          * Set how long the response should be cached.
 378          *
 379          * @param int $maxage
 380          */
 381         public function setCacheMaxAge( $maxage ) {
 382                 $this->setCacheControl( [
 383                         'max-age' => $maxage,
 384                         's-maxage' => $maxage
 385                 ] );
 386         }
 387
 388         /**
 389          * Set the type of caching headers which will be sent.
 390          *
 391          * @param string $mode One of:
 392          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 393          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 394          *         not provided by any of these means, the object will be private.
 395          *    - 'private':    Cache this object only in private client-side caches.
 396          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 397          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 398          *         set consistently for a given URL, it cannot be set differently depending on
 399          *         things like the contents of the database, or whether the user is logged in.
 400          *
 401          *  If the wiki does not allow anonymous users to read it, the mode set here
 402          *  will be ignored, and private caching headers will always be sent. In other words,
 403          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 404          *  view.
 405          *
 406          *  For user-dependent data, the private mode should generally be used. The
 407          *  anon-public-user-private mode should only be used where there is a particularly
 408          *  good performance reason for caching the anonymous response, but where the
 409          *  response to logged-in users may differ, or may contain private data.
 410          *
 411          *  If this function is never called, then the default will be the private mode.
 412          */
 413         public function setCacheMode( $mode ) {
 414                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 415                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 416
 417                         // Ignore for forwards-compatibility
 418                         return;
 419                 }
 420
 421                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 422                         // Private wiki, only private headers
 423                         if ( $mode !== 'private' ) {
 424                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 425
 426                                 return;
 427                         }
 428                 }
 429
 430                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 431                         // User language is used for i18n, so we don't want to publicly
 432                         // cache. Anons are ok, because if they have non-default language
 433                         // then there's an appropriate Vary header set by whatever set
 434                         // their non-default language.
 435                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 436                                 "'anon-public-user-private' due to uselang=user\n" );
 437                         $mode = 'anon-public-user-private';
 438                 }
 439
 440                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 441                 $this->mCacheMode = $mode;
 442         }
 443
 444         /**
 445          * Set directives (key/value pairs) for the Cache-Control header.
 446          * Boolean values will be formatted as such, by including or omitting
 447          * without an equals sign.
 448          *
 449          * Cache control values set here will only be used if the cache mode is not
 450          * private, see setCacheMode().
 451          *
 452          * @param array $directives
 453          */
 454         public function setCacheControl( $directives ) {
 455                 $this->mCacheControl = $directives + $this->mCacheControl;
 456         }
 457
 458         /**
 459          * Create an instance of an output formatter by its name
 460          *
 461          * @param string $format
 462          *
 463          * @return ApiFormatBase
 464          */
 465         public function createPrinterByName( $format ) {
 466                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 467                 if ( $printer === null ) {
 468                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 469                 }
 470
 471                 return $printer;
 472         }
 473
 474         /**
 475          * Execute api request. Any errors will be handled if the API was called by the remote client.
 476          */
 477         public function execute() {
 478                 if ( $this->mInternalMode ) {
 479                         $this->executeAction();
 480                 } else {
 481                         $this->executeActionWithErrorHandling();
 482                 }
 483         }
 484
 485         /**
 486          * Execute an action, and in case of an error, erase whatever partial results
 487          * have been accumulated, and replace it with an error message and a help screen.
 488          */
 489         protected function executeActionWithErrorHandling() {
 490                 // Verify the CORS header before executing the action
 491                 if ( !$this->handleCORS() ) {
 492                         // handleCORS() has sent a 403, abort
 493                         return;
 494                 }
 495
 496                 // Exit here if the request method was OPTIONS
 497                 // (assume there will be a followup GET or POST)
 498                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 499                         return;
 500                 }
 501
 502                 // In case an error occurs during data output,
 503                 // clear the output buffer and print just the error information
 504                 $obLevel = ob_get_level();
 505                 ob_start();
 506
 507                 $t = microtime( true );
 508                 $isError = false;
 509                 try {
 510                         $this->executeAction();
 511                         $runTime = microtime( true ) - $t;
 512                         $this->logRequest( $runTime );
 513                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 514                                 $this->getStats()->timing(
 515                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 516                                 );
 517                         }
 518                 } catch ( Exception $e ) {
 519                         $this->handleException( $e );
 520                         $this->logRequest( microtime( true ) - $t, $e );
 521                         $isError = true;
 522                 }
 523
 524                 // Commit DBs and send any related cookies and headers
 525                 MediaWiki::preOutputCommit( $this->getContext() );
 526
 527                 // Send cache headers after any code which might generate an error, to
 528                 // avoid sending public cache headers for errors.
 529                 $this->sendCacheHeaders( $isError );
 530
 531                 // Executing the action might have already messed with the output
 532                 // buffers.
 533                 while ( ob_get_level() > $obLevel ) {
 534                         ob_end_flush();
 535                 }
 536         }
 537
 538         /**
 539          * Handle an exception as an API response
 540          *
 541          * @since 1.23
 542          * @param Exception $e
 543          */
 544         protected function handleException( Exception $e ) {
 545                 // Bug 63145: Rollback any open database transactions
 546                 if ( !( $e instanceof UsageException ) ) {
 547                         // UsageExceptions are intentional, so don't rollback if that's the case
 548                         try {
 549                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 550                         } catch ( DBError $e2 ) {
 551                                 // Rollback threw an exception too. Log it, but don't interrupt
 552                                 // our regularly scheduled exception handling.
 553                                 MWExceptionHandler::logException( $e2 );
 554                         }
 555                 }
 556
 557                 // Allow extra cleanup and logging
 558                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 559
 560                 // Log it
 561                 if ( !( $e instanceof UsageException ) ) {
 562                         MWExceptionHandler::logException( $e );
 563                 }
 564
 565                 // Handle any kind of exception by outputting properly formatted error message.
 566                 // If this fails, an unhandled exception should be thrown so that global error
 567                 // handler will process and log it.
 568
 569                 $errCode = $this->substituteResultWithError( $e );
 570
 571                 // Error results should not be cached
 572                 $this->setCacheMode( 'private' );
 573
 574                 $response = $this->getRequest()->response();
 575                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 576                 if ( $e->getCode() === 0 ) {
 577                         $response->header( $headerStr );
 578                 } else {
 579                         $response->header( $headerStr, true, $e->getCode() );
 580                 }
 581
 582                 // Reset and print just the error message
 583                 ob_clean();
 584
 585                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 586                 $this->createErrorPrinter();
 587
 588                 try {
 589                         $this->printResult( true );
 590                 } catch ( UsageException $ex ) {
 591                         // The error printer itself is failing. Try suppressing its request
 592                         // parameters and redo.
 593                         $this->setWarning(
 594                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 595                         );
 596                         $this->mPrinter = null;
 597                         $this->createErrorPrinter();
 598                         $this->mPrinter->forceDefaultParams();
 599                         $this->printResult( true );
 600                 }
 601         }
 602
 603         /**
 604          * Handle an exception from the ApiBeforeMain hook.
 605          *
 606          * This tries to print the exception as an API response, to be more
 607          * friendly to clients. If it fails, it will rethrow the exception.
 608          *
 609          * @since 1.23
 610          * @param Exception $e
 611          * @throws Exception
 612          */
 613         public static function handleApiBeforeMainException( Exception $e ) {
 614                 ob_start();
 615
 616                 try {
 617                         $main = new self( RequestContext::getMain(), false );
 618                         $main->handleException( $e );
 619                         $main->logRequest( 0, $e );
 620                 } catch ( Exception $e2 ) {
 621                         // Nope, even that didn't work. Punt.
 622                         throw $e;
 623                 }
 624
 625                 // Reset cache headers
 626                 $main->sendCacheHeaders( true );
 627
 628                 ob_end_flush();
 629         }
 630
 631         /**
 632          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 633          *
 634          * If no origin parameter is present, nothing happens.
 635          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 636          * is set and false is returned.
 637          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 638          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 639          * headers are set.
 640          * http://www.w3.org/TR/cors/#resource-requests
 641          * http://www.w3.org/TR/cors/#resource-preflight-requests
 642          *
 643          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 644          */
 645         protected function handleCORS() {
 646                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 647                 if ( $originParam === null ) {
 648                         // No origin parameter, nothing to do
 649                         return true;
 650                 }
 651
 652                 $request = $this->getRequest();
 653                 $response = $request->response();
 654
 655                 $matchOrigin = false;
 656                 $allowTiming = false;
 657                 $varyOrigin = true;
 658
 659                 if ( $originParam === '*' ) {
 660                         // Request for anonymous CORS
 661                         $matchOrigin = true;
 662                         $allowOrigin = '*';
 663                         $allowCredentials = 'false';
 664                         $varyOrigin = false; // No need to vary
 665                 } else {
 666                         // Non-anonymous CORS, check we allow the domain
 667
 668                         // Origin: header is a space-separated list of origins, check all of them
 669                         $originHeader = $request->getHeader( 'Origin' );
 670                         if ( $originHeader === false ) {
 671                                 $origins = [];
 672                         } else {
 673                                 $originHeader = trim( $originHeader );
 674                                 $origins = preg_split( '/\s+/', $originHeader );
 675                         }
 676
 677                         if ( !in_array( $originParam, $origins ) ) {
 678                                 // origin parameter set but incorrect
 679                                 // Send a 403 response
 680                                 $response->statusHeader( 403 );
 681                                 $response->header( 'Cache-Control: no-cache' );
 682                                 echo "'origin' parameter does not match Origin header\n";
 683
 684                                 return false;
 685                         }
 686
 687                         $config = $this->getConfig();
 688                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 689                                 $originParam,
 690                                 $config->get( 'CrossSiteAJAXdomains' ),
 691                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 692                         );
 693
 694                         $allowOrigin = $originHeader;
 695                         $allowCredentials = 'true';
 696                         $allowTiming = $originHeader;
 697                 }
 698
 699                 if ( $matchOrigin ) {
 700                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 701                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 702                         if ( $preflight ) {
 703                                 // This is a CORS preflight request
 704                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 705                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 706                                         return true;
 707                                 }
 708                                 // We allow the actual request to send the following headers
 709                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 710                                 if ( $requestedHeaders !== false ) {
 711                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 712                                                 return true;
 713                                         }
 714                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 715                                 }
 716
 717                                 // We only allow the actual request to be GET or POST
 718                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 719                         }
 720
 721                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 722                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 723                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 724                         if ( $allowTiming !== false ) {
 725                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 726                         }
 727
 728                         if ( !$preflight ) {
 729                                 $response->header(
 730                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 731                                 );
 732                         }
 733                 }
 734
 735                 if ( $varyOrigin ) {
 736                         $this->getOutput()->addVaryHeader( 'Origin' );
 737                 }
 738
 739                 return true;
 740         }
 741
 742         /**
 743          * Attempt to match an Origin header against a set of rules and a set of exceptions
 744          * @param string $value Origin header
 745          * @param array $rules Set of wildcard rules
 746          * @param array $exceptions Set of wildcard rules
 747          * @return bool True if $value matches a rule in $rules and doesn't match
 748          *    any rules in $exceptions, false otherwise
 749          */
 750         protected static function matchOrigin( $value, $rules, $exceptions ) {
 751                 foreach ( $rules as $rule ) {
 752                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 753                                 // Rule matches, check exceptions
 754                                 foreach ( $exceptions as $exc ) {
 755                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 756                                                 return false;
 757                                         }
 758                                 }
 759
 760                                 return true;
 761                         }
 762                 }
 763
 764                 return false;
 765         }
 766
 767         /**
 768          * Attempt to validate the value of Access-Control-Request-Headers against a list
 769          * of headers that we allow the follow up request to send.
 770          *
 771          * @param string $requestedHeaders Comma seperated list of HTTP headers
 772          * @return bool True if all requested headers are in the list of allowed headers
 773          */
 774         protected static function matchRequestedHeaders( $requestedHeaders ) {
 775                 if ( trim( $requestedHeaders ) === '' ) {
 776                         return true;
 777                 }
 778                 $requestedHeaders = explode( ',', $requestedHeaders );
 779                 $allowedAuthorHeaders = array_flip( [
 780                         /* simple headers (see spec) */
 781                         'accept',
 782                         'accept-language',
 783                         'content-language',
 784                         'content-type',
 785                         /* non-authorable headers in XHR, which are however requested by some UAs */
 786                         'accept-encoding',
 787                         'dnt',
 788                         'origin',
 789                         /* MediaWiki whitelist */
 790                         'api-user-agent',
 791                 ] );
 792                 foreach ( $requestedHeaders as $rHeader ) {
 793                         $rHeader = strtolower( trim( $rHeader ) );
 794                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 795                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 796                                 return false;
 797                         }
 798                 }
 799                 return true;
 800         }
 801
 802         /**
 803          * Helper function to convert wildcard string into a regex
 804          * '*' => '.*?'
 805          * '?' => '.'
 806          *
 807          * @param string $wildcard String with wildcards
 808          * @return string Regular expression
 809          */
 810         protected static function wildcardToRegex( $wildcard ) {
 811                 $wildcard = preg_quote( $wildcard, '/' );
 812                 $wildcard = str_replace(
 813                         [ '\*', '\?' ],
 814                         [ '.*?', '.' ],
 815                         $wildcard
 816                 );
 817
 818                 return "/^https?:\/\/$wildcard$/";
 819         }
 820
 821         /**
 822          * Send caching headers
 823          * @param bool $isError Whether an error response is being output
 824          * @since 1.26 added $isError parameter
 825          */
 826         protected function sendCacheHeaders( $isError ) {
 827                 $response = $this->getRequest()->response();
 828                 $out = $this->getOutput();
 829
 830                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 831
 832                 $config = $this->getConfig();
 833
 834                 if ( $config->get( 'VaryOnXFP' ) ) {
 835                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 836                 }
 837
 838                 if ( !$isError && $this->mModule &&
 839                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 840                 ) {
 841                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 842                         if ( $etag !== null ) {
 843                                 $response->header( "ETag: $etag" );
 844                         }
 845                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 846                         if ( $lastMod !== null ) {
 847                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 848                         }
 849                 }
 850
 851                 // The logic should be:
 852                 // $this->mCacheControl['max-age'] is set?
 853                 //    Use it, the module knows better than our guess.
 854                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 855                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 856                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 857                 $maxage = 0;
 858                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 859                         $maxage = $this->mCacheControl['max-age'];
 860                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 861                         $this->mCacheMode !== 'private'
 862                 ) {
 863                         $maxage = $this->getParameter( 'maxage' );
 864                 }
 865                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 866
 867                 if ( $this->mCacheMode == 'private' ) {
 868                         $response->header( "Cache-Control: $privateCache" );
 869                         return;
 870                 }
 871
 872                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 873                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 874                         $out->addVaryHeader( 'Cookie' );
 875                         $response->header( $out->getVaryHeader() );
 876                         if ( $useKeyHeader ) {
 877                                 $response->header( $out->getKeyHeader() );
 878                                 if ( $out->haveCacheVaryCookies() ) {
 879                                         // Logged in, mark this request private
 880                                         $response->header( "Cache-Control: $privateCache" );
 881                                         return;
 882                                 }
 883                                 // Logged out, send normal public headers below
 884                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 885                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 886                                 // Mark request private
 887                                 $response->header( "Cache-Control: $privateCache" );
 888
 889                                 return;
 890                         } // else no Key and anonymous, send public headers below
 891                 }
 892
 893                 // Send public headers
 894                 $response->header( $out->getVaryHeader() );
 895                 if ( $useKeyHeader ) {
 896                         $response->header( $out->getKeyHeader() );
 897                 }
 898
 899                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 900                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 901                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 902                 }
 903                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 904                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 905                 }
 906
 907                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 908                         // Public cache not requested
 909                         // Sending a Vary header in this case is harmless, and protects us
 910                         // against conditional calls of setCacheMaxAge().
 911                         $response->header( "Cache-Control: $privateCache" );
 912
 913                         return;
 914                 }
 915
 916                 $this->mCacheControl['public'] = true;
 917
 918                 // Send an Expires header
 919                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 920                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 921                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 922
 923                 // Construct the Cache-Control header
 924                 $ccHeader = '';
 925                 $separator = '';
 926                 foreach ( $this->mCacheControl as $name => $value ) {
 927                         if ( is_bool( $value ) ) {
 928                                 if ( $value ) {
 929                                         $ccHeader .= $separator . $name;
 930                                         $separator = ', ';
 931                                 }
 932                         } else {
 933                                 $ccHeader .= $separator . "$name=$value";
 934                                 $separator = ', ';
 935                         }
 936                 }
 937
 938                 $response->header( "Cache-Control: $ccHeader" );
 939         }
 940
 941         /**
 942          * Create the printer for error output
 943          */
 944         private function createErrorPrinter() {
 945                 if ( !isset( $this->mPrinter ) ) {
 946                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 947                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 948                                 $value = self::API_DEFAULT_FORMAT;
 949                         }
 950                         $this->mPrinter = $this->createPrinterByName( $value );
 951                 }
 952
 953                 // Printer may not be able to handle errors. This is particularly
 954                 // likely if the module returns something for getCustomPrinter().
 955                 if ( !$this->mPrinter->canPrintErrors() ) {
 956                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 957                 }
 958         }
 959
 960         /**
 961          * Create an error message for the given exception.
 962          *
 963          * If the exception is a UsageException then
 964          * UsageException::getMessageArray() will be called to create the message.
 965          *
 966          * @param Exception $e
 967          * @return array ['code' => 'some string', 'info' => 'some other string']
 968          * @since 1.27
 969          */
 970         protected function errorMessageFromException( $e ) {
 971                 if ( $e instanceof UsageException ) {
 972                         // User entered incorrect parameters - generate error response
 973                         $errMessage = $e->getMessageArray();
 974                 } else {
 975                         $config = $this->getConfig();
 976                         // Something is seriously wrong
 977                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 978                                 $info = 'Database query error';
 979                         } else {
 980                                 $info = "Exception Caught: {$e->getMessage()}";
 981                         }
 982
 983                         $errMessage = [
 984                                 'code' => 'internal_api_error_' . get_class( $e ),
 985                                 'info' => '[' . WebRequest::getRequestId() . '] ' . $info,
 986                         ];
 987                 }
 988                 return $errMessage;
 989         }
 990
 991         /**
 992          * Replace the result data with the information about an exception.
 993          * Returns the error code
 994          * @param Exception $e
 995          * @return string
 996          */
 997         protected function substituteResultWithError( $e ) {
 998                 $result = $this->getResult();
 999                 $config = $this->getConfig();
1000
1001                 $errMessage = $this->errorMessageFromException( $e );
1002                 if ( $e instanceof UsageException ) {
1003                         // User entered incorrect parameters - generate error response
1004                         $link = wfExpandUrl( wfScript( 'api' ) );
1005                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
1006                 } else {
1007                         // Something is seriously wrong
1008                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1009                                 ApiResult::setContentValue(
1010                                         $errMessage,
1011                                         'trace',
1012                                         MWExceptionHandler::getRedactedTraceAsString( $e )
1013                                 );
1014                         }
1015                 }
1016
1017                 // Remember all the warnings to re-add them later
1018                 $warnings = $result->getResultData( [ 'warnings' ] );
1019
1020                 $result->reset();
1021                 // Re-add the id
1022                 $requestid = $this->getParameter( 'requestid' );
1023                 if ( !is_null( $requestid ) ) {
1024                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1025                 }
1026                 if ( $config->get( 'ShowHostnames' ) ) {
1027                         // servedby is especially useful when debugging errors
1028                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1029                 }
1030                 if ( $warnings !== null ) {
1031                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1032                 }
1033
1034                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
1035
1036                 return $errMessage['code'];
1037         }
1038
1039         /**
1040          * Set up for the execution.
1041          * @return array
1042          */
1043         protected function setupExecuteAction() {
1044                 // First add the id to the top element
1045                 $result = $this->getResult();
1046                 $requestid = $this->getParameter( 'requestid' );
1047                 if ( !is_null( $requestid ) ) {
1048                         $result->addValue( null, 'requestid', $requestid );
1049                 }
1050
1051                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1052                         $servedby = $this->getParameter( 'servedby' );
1053                         if ( $servedby ) {
1054                                 $result->addValue( null, 'servedby', wfHostname() );
1055                         }
1056                 }
1057
1058                 if ( $this->getParameter( 'curtimestamp' ) ) {
1059                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1060                                 ApiResult::NO_SIZE_CHECK );
1061                 }
1062
1063                 $params = $this->extractRequestParams();
1064
1065                 $this->mAction = $params['action'];
1066
1067                 if ( !is_string( $this->mAction ) ) {
1068                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1069                 }
1070
1071                 return $params;
1072         }
1073
1074         /**
1075          * Set up the module for response
1076          * @return ApiBase The module that will handle this action
1077          * @throws MWException
1078          * @throws UsageException
1079          */
1080         protected function setupModule() {
1081                 // Instantiate the module requested by the user
1082                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1083                 if ( $module === null ) {
1084                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1085                 }
1086                 $moduleParams = $module->extractRequestParams();
1087
1088                 // Check token, if necessary
1089                 if ( $module->needsToken() === true ) {
1090                         throw new MWException(
1091                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1092                                 'See documentation for ApiBase::needsToken for details.'
1093                         );
1094                 }
1095                 if ( $module->needsToken() ) {
1096                         if ( !$module->mustBePosted() ) {
1097                                 throw new MWException(
1098                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1099                                 );
1100                         }
1101
1102                         if ( !isset( $moduleParams['token'] ) ) {
1103                                 $this->dieUsageMsg( [ 'missingparam', 'token' ] );
1104                         }
1105
1106                         $module->requirePostedParameters( [ 'token' ] );
1107
1108                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1109                                 $this->dieUsageMsg( 'sessionfailure' );
1110                         }
1111                 }
1112
1113                 return $module;
1114         }
1115
1116         /**
1117          * Check the max lag if necessary
1118          * @param ApiBase $module Api module being used
1119          * @param array $params Array an array containing the request parameters.
1120          * @return bool True on success, false should exit immediately
1121          */
1122         protected function checkMaxLag( $module, $params ) {
1123                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1124                         $maxLag = $params['maxlag'];
1125                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1126                         if ( $lag > $maxLag ) {
1127                                 $response = $this->getRequest()->response();
1128
1129                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1130                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1131
1132                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1133                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1134                                 }
1135
1136                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1137                         }
1138                 }
1139
1140                 return true;
1141         }
1142
1143         /**
1144          * Check selected RFC 7232 precondition headers
1145          *
1146          * RFC 7232 envisions a particular model where you send your request to "a
1147          * resource", and for write requests that you can read "the resource" by
1148          * changing the method to GET. When the API receives a GET request, it
1149          * works out even though "the resource" from RFC 7232's perspective might
1150          * be many resources from MediaWiki's perspective. But it totally fails for
1151          * a POST, since what HTTP sees as "the resource" is probably just
1152          * "/api.php" with all the interesting bits in the body.
1153          *
1154          * Therefore, we only support RFC 7232 precondition headers for GET (and
1155          * HEAD). That means we don't need to bother with If-Match and
1156          * If-Unmodified-Since since they only apply to modification requests.
1157          *
1158          * And since we don't support Range, If-Range is ignored too.
1159          *
1160          * @since 1.26
1161          * @param ApiBase $module Api module being used
1162          * @return bool True on success, false should exit immediately
1163          */
1164         protected function checkConditionalRequestHeaders( $module ) {
1165                 if ( $this->mInternalMode ) {
1166                         // No headers to check in internal mode
1167                         return true;
1168                 }
1169
1170                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1171                         // Don't check POSTs
1172                         return true;
1173                 }
1174
1175                 $return304 = false;
1176
1177                 $ifNoneMatch = array_diff(
1178                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1179                         [ '' ]
1180                 );
1181                 if ( $ifNoneMatch ) {
1182                         if ( $ifNoneMatch === [ '*' ] ) {
1183                                 // API responses always "exist"
1184                                 $etag = '*';
1185                         } else {
1186                                 $etag = $module->getConditionalRequestData( 'etag' );
1187                         }
1188                 }
1189                 if ( $ifNoneMatch && $etag !== null ) {
1190                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1191                         $match = array_map( function ( $s ) {
1192                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1193                         }, $ifNoneMatch );
1194                         $return304 = in_array( $test, $match, true );
1195                 } else {
1196                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1197
1198                         // Some old browsers sends sizes after the date, like this:
1199                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1200                         // Ignore that.
1201                         $i = strpos( $value, ';' );
1202                         if ( $i !== false ) {
1203                                 $value = trim( substr( $value, 0, $i ) );
1204                         }
1205
1206                         if ( $value !== '' ) {
1207                                 try {
1208                                         $ts = new MWTimestamp( $value );
1209                                         if (
1210                                                 // RFC 7231 IMF-fixdate
1211                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1212                                                 // RFC 850
1213                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1214                                                 // asctime (with and without space-padded day)
1215                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1216                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1217                                         ) {
1218                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1219                                                 if ( $lastMod !== null ) {
1220                                                         // Mix in some MediaWiki modification times
1221                                                         $modifiedTimes = [
1222                                                                 'page' => $lastMod,
1223                                                                 'user' => $this->getUser()->getTouched(),
1224                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1225                                                         ];
1226                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1227                                                                 // T46570: the core page itself may not change, but resources might
1228                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1229                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1230                                                                 );
1231                                                         }
1232                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1233                                                         $lastMod = max( $modifiedTimes );
1234                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1235                                                 }
1236                                         }
1237                                 } catch ( TimestampException $e ) {
1238                                         // Invalid timestamp, ignore it
1239                                 }
1240                         }
1241                 }
1242
1243                 if ( $return304 ) {
1244                         $this->getRequest()->response()->statusHeader( 304 );
1245
1246                         // Avoid outputting the compressed representation of a zero-length body
1247                         MediaWiki\suppressWarnings();
1248                         ini_set( 'zlib.output_compression', 0 );
1249                         MediaWiki\restoreWarnings();
1250                         wfClearOutputBuffers();
1251
1252                         return false;
1253                 }
1254
1255                 return true;
1256         }
1257
1258         /**
1259          * Check for sufficient permissions to execute
1260          * @param ApiBase $module An Api module
1261          */
1262         protected function checkExecutePermissions( $module ) {
1263                 $user = $this->getUser();
1264                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1265                         !$user->isAllowed( 'read' )
1266                 ) {
1267                         $this->dieUsageMsg( 'readrequired' );
1268                 }
1269
1270                 if ( $module->isWriteMode() ) {
1271                         if ( !$this->mEnableWrite ) {
1272                                 $this->dieUsageMsg( 'writedisabled' );
1273                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1274                                 $this->dieUsageMsg( 'writerequired' );
1275                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1276                                 $this->dieUsage(
1277                                         'Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules',
1278                                         'promised-nonwrite-api'
1279                                 );
1280                         }
1281
1282                         $this->checkReadOnly( $module );
1283                 }
1284
1285                 // Allow extensions to stop execution for arbitrary reasons.
1286                 $message = false;
1287                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1288                         $this->dieUsageMsg( $message );
1289                 }
1290         }
1291
1292         /**
1293          * Check if the DB is read-only for this user
1294          * @param ApiBase $module An Api module
1295          */
1296         protected function checkReadOnly( $module ) {
1297                 if ( wfReadOnly() ) {
1298                         $this->dieReadOnly();
1299                 }
1300
1301                 if ( $module->isWriteMode()
1302                         && in_array( 'bot', $this->getUser()->getGroups() )
1303                         && wfGetLB()->getServerCount() > 1
1304                 ) {
1305                         $this->checkBotReadOnly();
1306                 }
1307         }
1308
1309         /**
1310          * Check whether we are readonly for bots
1311          */
1312         private function checkBotReadOnly() {
1313                 // Figure out how many servers have passed the lag threshold
1314                 $numLagged = 0;
1315                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1316                 $laggedServers = [];
1317                 $loadBalancer = wfGetLB();
1318                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1319                         if ( $lag > $lagLimit ) {
1320                                 ++$numLagged;
1321                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1322                         }
1323                 }
1324
1325                 // If a majority of replica DBs are too lagged then disallow writes
1326                 $replicaCount = wfGetLB()->getServerCount() - 1;
1327                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1328                         $laggedServers = implode( ', ', $laggedServers );
1329                         wfDebugLog(
1330                                 'api-readonly',
1331                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1332                         );
1333
1334                         $parsed = $this->parseMsg( [ 'readonlytext' ] );
1335                         $this->dieUsage(
1336                                 $parsed['info'],
1337                                 $parsed['code'],
1338                                 /* http error */
1339                                 0,
1340                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1341                         );
1342                 }
1343         }
1344
1345         /**
1346          * Check asserts of the user's rights
1347          * @param array $params
1348          */
1349         protected function checkAsserts( $params ) {
1350                 if ( isset( $params['assert'] ) ) {
1351                         $user = $this->getUser();
1352                         switch ( $params['assert'] ) {
1353                                 case 'user':
1354                                         if ( $user->isAnon() ) {
1355                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1356                                         }
1357                                         break;
1358                                 case 'bot':
1359                                         if ( !$user->isAllowed( 'bot' ) ) {
1360                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1361                                         }
1362                                         break;
1363                         }
1364                 }
1365         }
1366
1367         /**
1368          * Check POST for external response and setup result printer
1369          * @param ApiBase $module An Api module
1370          * @param array $params An array with the request parameters
1371          */
1372         protected function setupExternalResponse( $module, $params ) {
1373                 $request = $this->getRequest();
1374                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1375                         // Module requires POST. GET request might still be allowed
1376                         // if $wgDebugApi is true, otherwise fail.
1377                         $this->dieUsageMsgOrDebug( [ 'mustbeposted', $this->mAction ] );
1378                 }
1379
1380                 // See if custom printer is used
1381                 $this->mPrinter = $module->getCustomPrinter();
1382                 if ( is_null( $this->mPrinter ) ) {
1383                         // Create an appropriate printer
1384                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1385                 }
1386
1387                 if ( $request->getProtocol() === 'http' && (
1388                         $request->getSession()->shouldForceHTTPS() ||
1389                         ( $this->getUser()->isLoggedIn() &&
1390                                 $this->getUser()->requiresHTTPS() )
1391                 ) ) {
1392                         $this->logFeatureUsage( 'https-expected' );
1393                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1394                 }
1395         }
1396
1397         /**
1398          * Execute the actual module, without any error handling
1399          */
1400         protected function executeAction() {
1401                 $params = $this->setupExecuteAction();
1402                 $module = $this->setupModule();
1403                 $this->mModule = $module;
1404
1405                 if ( !$this->mInternalMode ) {
1406                         $this->setRequestExpectations( $module );
1407                 }
1408
1409                 $this->checkExecutePermissions( $module );
1410
1411                 if ( !$this->checkMaxLag( $module, $params ) ) {
1412                         return;
1413                 }
1414
1415                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1416                         return;
1417                 }
1418
1419                 if ( !$this->mInternalMode ) {
1420                         $this->setupExternalResponse( $module, $params );
1421                 }
1422
1423                 $this->checkAsserts( $params );
1424
1425                 // Execute
1426                 $module->execute();
1427                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1428
1429                 $this->reportUnusedParams();
1430
1431                 if ( !$this->mInternalMode ) {
1432                         // append Debug information
1433                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1434
1435                         // Print result data
1436                         $this->printResult( false );
1437                 }
1438         }
1439
1440         /**
1441          * Set database connection, query, and write expectations given this module request
1442          * @param ApiBase $module
1443          */
1444         protected function setRequestExpectations( ApiBase $module ) {
1445                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1446                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1447                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1448                 if ( $this->getRequest()->hasSafeMethod() ) {
1449                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1450                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1451                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1452                         $this->getRequest()->markAsSafeRequest();
1453                 } else {
1454                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1455                 }
1456         }
1457
1458         /**
1459          * Log the preceding request
1460          * @param float $time Time in seconds
1461          * @param Exception $e Exception caught while processing the request
1462          */
1463         protected function logRequest( $time, $e = null ) {
1464                 $request = $this->getRequest();
1465                 $logCtx = [
1466                         'ts' => time(),
1467                         'ip' => $request->getIP(),
1468                         'userAgent' => $this->getUserAgent(),
1469                         'wiki' => wfWikiID(),
1470                         'timeSpentBackend' => (int) round( $time * 1000 ),
1471                         'hadError' => $e !== null,
1472                         'errorCodes' => [],
1473                         'params' => [],
1474                 ];
1475
1476                 if ( $e ) {
1477                         $logCtx['errorCodes'][] = $this->errorMessageFromException( $e )['code'];
1478                 }
1479
1480                 // Construct space separated message for 'api' log channel
1481                 $msg = "API {$request->getMethod()} " .
1482                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1483                         " {$logCtx['ip']} " .
1484                         "T={$logCtx['timeSpentBackend']}ms";
1485
1486                 foreach ( $this->getParamsUsed() as $name ) {
1487                         $value = $request->getVal( $name );
1488                         if ( $value === null ) {
1489                                 continue;
1490                         }
1491
1492                         if ( strlen( $value ) > 256 ) {
1493                                 $value = substr( $value, 0, 256 );
1494                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1495                         } else {
1496                                 $encValue = $this->encodeRequestLogValue( $value );
1497                         }
1498
1499                         $logCtx['params'][$name] = $value;
1500                         $msg .= " {$name}={$encValue}";
1501                 }
1502
1503                 wfDebugLog( 'api', $msg, 'private' );
1504                 // ApiAction channel is for structured data consumers
1505                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1506         }
1507
1508         /**
1509          * Encode a value in a format suitable for a space-separated log line.
1510          * @param string $s
1511          * @return string
1512          */
1513         protected function encodeRequestLogValue( $s ) {
1514                 static $table;
1515                 if ( !$table ) {
1516                         $chars = ';@$!*(),/:';
1517                         $numChars = strlen( $chars );
1518                         for ( $i = 0; $i < $numChars; $i++ ) {
1519                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1520                         }
1521                 }
1522
1523                 return strtr( rawurlencode( $s ), $table );
1524         }
1525
1526         /**
1527          * Get the request parameters used in the course of the preceding execute() request
1528          * @return array
1529          */
1530         protected function getParamsUsed() {
1531                 return array_keys( $this->mParamsUsed );
1532         }
1533
1534         /**
1535          * Mark parameters as used
1536          * @param string|string[] $params
1537          */
1538         public function markParamsUsed( $params ) {
1539                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1540         }
1541
1542         /**
1543          * Get a request value, and register the fact that it was used, for logging.
1544          * @param string $name
1545          * @param mixed $default
1546          * @return mixed
1547          */
1548         public function getVal( $name, $default = null ) {
1549                 $this->mParamsUsed[$name] = true;
1550
1551                 $ret = $this->getRequest()->getVal( $name );
1552                 if ( $ret === null ) {
1553                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1554                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1555                                 // array.
1556                                 $this->setWarning(
1557                                         "Parameter '$name' uses unsupported PHP array syntax"
1558                                 );
1559                         }
1560                         $ret = $default;
1561                 }
1562                 return $ret;
1563         }
1564
1565         /**
1566          * Get a boolean request value, and register the fact that the parameter
1567          * was used, for logging.
1568          * @param string $name
1569          * @return bool
1570          */
1571         public function getCheck( $name ) {
1572                 return $this->getVal( $name, null ) !== null;
1573         }
1574
1575         /**
1576          * Get a request upload, and register the fact that it was used, for logging.
1577          *
1578          * @since 1.21
1579          * @param string $name Parameter name
1580          * @return WebRequestUpload
1581          */
1582         public function getUpload( $name ) {
1583                 $this->mParamsUsed[$name] = true;
1584
1585                 return $this->getRequest()->getUpload( $name );
1586         }
1587
1588         /**
1589          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1590          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1591          */
1592         protected function reportUnusedParams() {
1593                 $paramsUsed = $this->getParamsUsed();
1594                 $allParams = $this->getRequest()->getValueNames();
1595
1596                 if ( !$this->mInternalMode ) {
1597                         // Printer has not yet executed; don't warn that its parameters are unused
1598                         $printerParams = array_map(
1599                                 [ $this->mPrinter, 'encodeParamName' ],
1600                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1601                         );
1602                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1603                 } else {
1604                         $unusedParams = array_diff( $allParams, $paramsUsed );
1605                 }
1606
1607                 if ( count( $unusedParams ) ) {
1608                         $s = count( $unusedParams ) > 1 ? 's' : '';
1609                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1610                 }
1611         }
1612
1613         /**
1614          * Print results using the current printer
1615          *
1616          * @param bool $isError
1617          */
1618         protected function printResult( $isError ) {
1619                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1620                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1621                 }
1622
1623                 $printer = $this->mPrinter;
1624                 $printer->initPrinter( false );
1625                 $printer->execute();
1626                 $printer->closePrinter();
1627         }
1628
1629         /**
1630          * @return bool
1631          */
1632         public function isReadMode() {
1633                 return false;
1634         }
1635
1636         /**
1637          * See ApiBase for description.
1638          *
1639          * @return array
1640          */
1641         public function getAllowedParams() {
1642                 return [
1643                         'action' => [
1644                                 ApiBase::PARAM_DFLT => 'help',
1645                                 ApiBase::PARAM_TYPE => 'submodule',
1646                         ],
1647                         'format' => [
1648                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1649                                 ApiBase::PARAM_TYPE => 'submodule',
1650                         ],
1651                         'maxlag' => [
1652                                 ApiBase::PARAM_TYPE => 'integer'
1653                         ],
1654                         'smaxage' => [
1655                                 ApiBase::PARAM_TYPE => 'integer',
1656                                 ApiBase::PARAM_DFLT => 0
1657                         ],
1658                         'maxage' => [
1659                                 ApiBase::PARAM_TYPE => 'integer',
1660                                 ApiBase::PARAM_DFLT => 0
1661                         ],
1662                         'assert' => [
1663                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1664                         ],
1665                         'requestid' => null,
1666                         'servedby' => false,
1667                         'curtimestamp' => false,
1668                         'origin' => null,
1669                         'uselang' => [
1670                                 ApiBase::PARAM_DFLT => 'user',
1671                         ],
1672                 ];
1673         }
1674
1675         /** @see ApiBase::getExamplesMessages() */
1676         protected function getExamplesMessages() {
1677                 return [
1678                         'action=help'
1679                                 => 'apihelp-help-example-main',
1680                         'action=help&recursivesubmodules=1'
1681                                 => 'apihelp-help-example-recursive',
1682                 ];
1683         }
1684
1685         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1686                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1687                 // reindex the array to get 'permissions' in the right place.
1688                 $oldHelp = $help;
1689                 $help = [];
1690                 foreach ( $oldHelp as $k => $v ) {
1691                         if ( $k === 'submodules' ) {
1692                                 $help['permissions'] = '';
1693                         }
1694                         $help[$k] = $v;
1695                 }
1696                 $help['datatypes'] = '';
1697                 $help['credits'] = '';
1698
1699                 // Fill 'permissions'
1700                 $help['permissions'] .= Html::openElement( 'div',
1701                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1702                 $m = $this->msg( 'api-help-permissions' );
1703                 if ( !$m->isDisabled() ) {
1704                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1705                                 $m->numParams( count( self::$mRights ) )->parse()
1706                         );
1707                 }
1708                 $help['permissions'] .= Html::openElement( 'dl' );
1709                 foreach ( self::$mRights as $right => $rightMsg ) {
1710                         $help['permissions'] .= Html::element( 'dt', null, $right );
1711
1712                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1713                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1714
1715                         $groups = array_map( function ( $group ) {
1716                                 return $group == '*' ? 'all' : $group;
1717                         }, User::getGroupsWithPermission( $right ) );
1718
1719                         $help['permissions'] .= Html::rawElement( 'dd', null,
1720                                 $this->msg( 'api-help-permissions-granted-to' )
1721                                         ->numParams( count( $groups ) )
1722                                         ->params( $this->getLanguage()->commaList( $groups ) )
1723                                         ->parse()
1724                         );
1725                 }
1726                 $help['permissions'] .= Html::closeElement( 'dl' );
1727                 $help['permissions'] .= Html::closeElement( 'div' );
1728
1729                 // Fill 'datatypes' and 'credits', if applicable
1730                 if ( empty( $options['nolead'] ) ) {
1731                         $level = $options['headerlevel'];
1732                         $tocnumber = &$options['tocnumber'];
1733
1734                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1735
1736                         // Add an additional span with sanitized ID
1737                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1738                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1739                                         $header;
1740                         }
1741                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1742                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1743                                 $header
1744                         );
1745                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1746                         if ( !isset( $tocData['main/datatypes'] ) ) {
1747                                 $tocnumber[$level]++;
1748                                 $tocData['main/datatypes'] = [
1749                                         'toclevel' => count( $tocnumber ),
1750                                         'level' => $level,
1751                                         'anchor' => 'main/datatypes',
1752                                         'line' => $header,
1753                                         'number' => implode( '.', $tocnumber ),
1754                                         'index' => false,
1755                                 ];
1756                         }
1757
1758                         // Add an additional span with sanitized ID
1759                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1760                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1761                                         $header;
1762                         }
1763                         $header = $this->msg( 'api-credits-header' )->parse();
1764                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1765                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1766                                 $header
1767                         );
1768                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1769                         if ( !isset( $tocData['main/credits'] ) ) {
1770                                 $tocnumber[$level]++;
1771                                 $tocData['main/credits'] = [
1772                                         'toclevel' => count( $tocnumber ),
1773                                         'level' => $level,
1774                                         'anchor' => 'main/credits',
1775                                         'line' => $header,
1776                                         'number' => implode( '.', $tocnumber ),
1777                                         'index' => false,
1778                                 ];
1779                         }
1780                 }
1781         }
1782
1783         private $mCanApiHighLimits = null;
1784
1785         /**
1786          * Check whether the current user is allowed to use high limits
1787          * @return bool
1788          */
1789         public function canApiHighLimits() {
1790                 if ( !isset( $this->mCanApiHighLimits ) ) {
1791                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1792                 }
1793
1794                 return $this->mCanApiHighLimits;
1795         }
1796
1797         /**
1798          * Overrides to return this instance's module manager.
1799          * @return ApiModuleManager
1800          */
1801         public function getModuleManager() {
1802                 return $this->mModuleMgr;
1803         }
1804
1805         /**
1806          * Fetches the user agent used for this request
1807          *
1808          * The value will be the combination of the 'Api-User-Agent' header (if
1809          * any) and the standard User-Agent header (if any).
1810          *
1811          * @return string
1812          */
1813         public function getUserAgent() {
1814                 return trim(
1815                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1816                         $this->getRequest()->getHeader( 'User-agent' )
1817                 );
1818         }
1819
1820         /************************************************************************//**
1821          * @name   Deprecated
1822          * @{
1823          */
1824
1825         /**
1826          * Sets whether the pretty-printer should format *bold* and $italics$
1827          *
1828          * @deprecated since 1.25
1829          * @param bool $help
1830          */
1831         public function setHelp( $help = true ) {
1832                 wfDeprecated( __METHOD__, '1.25' );
1833                 $this->mPrinter->setHelp( $help );
1834         }
1835
1836         /**
1837          * Override the parent to generate help messages for all available modules.
1838          *
1839          * @deprecated since 1.25
1840          * @return string
1841          */
1842         public function makeHelpMsg() {
1843                 wfDeprecated( __METHOD__, '1.25' );
1844
1845                 $this->setHelp();
1846                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1847
1848                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1849                         wfMemcKey(
1850                                 'apihelp',
1851                                 $this->getModuleName(),
1852                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1853                         ),
1854                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1855                         [ $this, 'reallyMakeHelpMsg' ]
1856                 );
1857         }
1858
1859         /**
1860          * @deprecated since 1.25
1861          * @return mixed|string
1862          */
1863         public function reallyMakeHelpMsg() {
1864                 wfDeprecated( __METHOD__, '1.25' );
1865                 $this->setHelp();
1866
1867                 // Use parent to make default message for the main module
1868                 $msg = parent::makeHelpMsg();
1869
1870                 $asterisks = str_repeat( '*** ', 14 );
1871                 $msg .= "\n\n$asterisks Modules  $asterisks\n\n";
1872
1873                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1874                         $module = $this->mModuleMgr->getModule( $name );
1875                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1876
1877                         $msg2 = $module->makeHelpMsg();
1878                         if ( $msg2 !== false ) {
1879                                 $msg .= $msg2;
1880                         }
1881                         $msg .= "\n";
1882                 }
1883
1884                 $msg .= "\n$asterisks Permissions $asterisks\n\n";
1885                 foreach ( self::$mRights as $right => $rightMsg ) {
1886                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1887                                 ->useDatabase( false )
1888                                 ->inLanguage( 'en' )
1889                                 ->text();
1890                         $groups = User::getGroupsWithPermission( $right );
1891                         $msg .= '* ' . $right . " *\n  $rightsMsg" .
1892                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1893                 }
1894
1895                 $msg .= "\n$asterisks Formats  $asterisks\n\n";
1896                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1897                         $module = $this->mModuleMgr->getModule( $name );
1898                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1899                         $msg2 = $module->makeHelpMsg();
1900                         if ( $msg2 !== false ) {
1901                                 $msg .= $msg2;
1902                         }
1903                         $msg .= "\n";
1904                 }
1905
1906                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1907                 $credits = str_replace( "\n", "\n   ", $credits );
1908                 $msg .= "\n*** Credits: ***\n   $credits\n";
1909
1910                 return $msg;
1911         }
1912
1913         /**
1914          * @deprecated since 1.25
1915          * @param ApiBase $module
1916          * @param string $paramName What type of request is this? e.g. action,
1917          *    query, list, prop, meta, format
1918          * @return string
1919          */
1920         public static function makeHelpMsgHeader( $module, $paramName ) {
1921                 wfDeprecated( __METHOD__, '1.25' );
1922                 $modulePrefix = $module->getModulePrefix();
1923                 if ( strval( $modulePrefix ) !== '' ) {
1924                         $modulePrefix = "($modulePrefix) ";
1925                 }
1926
1927                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1928         }
1929
1930         /**@}*/
1931
1932 }
1933
1934 /**
1935  * This exception will be thrown when dieUsage is called to stop module execution.
1936  *
1937  * @ingroup API
1938  */
1939 class UsageException extends MWException {
1940
1941         private $mCodestr;
1942
1943         /**
1944          * @var null|array
1945          */
1946         private $mExtraData;
1947
1948         /**
1949          * @param string $message
1950          * @param string $codestr
1951          * @param int $code
1952          * @param array|null $extradata
1953          */
1954         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1955                 parent::__construct( $message, $code );
1956                 $this->mCodestr = $codestr;
1957                 $this->mExtraData = $extradata;
1958
1959                 // This should never happen, so throw an exception about it that will
1960                 // hopefully get logged with a backtrace (T138585)
1961                 if ( !is_string( $codestr ) || $codestr === '' ) {
1962                         throw new InvalidArgumentException( 'Invalid $codestr, was ' .
1963                                 ( $codestr === '' ? 'empty string' : gettype( $codestr ) )
1964                         );
1965                 }
1966         }
1967
1968         /**
1969          * @return string
1970          */
1971         public function getCodeString() {
1972                 return $this->mCodestr;
1973         }
1974
1975         /**
1976          * @return array
1977          */
1978         public function getMessageArray() {
1979                 $result = [
1980                         'code' => $this->mCodestr,
1981                         'info' => $this->getMessage()
1982                 ];
1983                 if ( is_array( $this->mExtraData ) ) {
1984                         $result = array_merge( $result, $this->mExtraData );
1985                 }
1986
1987                 return $result;
1988         }
1989
1990         /**
1991          * @return string
1992          */
1993         public function __toString() {
1994                 return "{$this->getCodeString()}: {$this->getMessage()}";
1995         }
1996 }
1997
1998 /**
1999  * For really cool vim folding this needs to be at the end:
2000  * vim: foldmarker=@{,@} foldmethod=marker
2001  */