includes/api/ApiMain.php

   1 <?php
   2 /**
   3  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @defgroup API API
  22  */
  23
  24 use MediaWiki\Logger\LoggerFactory;
  25 use MediaWiki\MediaWikiServices;
  26 use Wikimedia\Timestamp\TimestampException;
  27 use Wikimedia\Rdbms\DBQueryError;
  28 use Wikimedia\Rdbms\DBError;
  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          * When no uselang parameter is given, this language will be used
  51          */
  52         const API_DEFAULT_USELANG = 'user';
  53
  54         /**
  55          * List of available modules: action name => module class
  56          */
  57         private static $Modules = [
  58                 'login' => ApiLogin::class,
  59                 'clientlogin' => ApiClientLogin::class,
  60                 'logout' => ApiLogout::class,
  61                 'createaccount' => ApiAMCreateAccount::class,
  62                 'linkaccount' => ApiLinkAccount::class,
  63                 'unlinkaccount' => ApiRemoveAuthenticationData::class,
  64                 'changeauthenticationdata' => ApiChangeAuthenticationData::class,
  65                 'removeauthenticationdata' => ApiRemoveAuthenticationData::class,
  66                 'resetpassword' => ApiResetPassword::class,
  67                 'query' => ApiQuery::class,
  68                 'expandtemplates' => ApiExpandTemplates::class,
  69                 'parse' => ApiParse::class,
  70                 'stashedit' => ApiStashEdit::class,
  71                 'opensearch' => ApiOpenSearch::class,
  72                 'feedcontributions' => ApiFeedContributions::class,
  73                 'feedrecentchanges' => ApiFeedRecentChanges::class,
  74                 'feedwatchlist' => ApiFeedWatchlist::class,
  75                 'help' => ApiHelp::class,
  76                 'paraminfo' => ApiParamInfo::class,
  77                 'rsd' => ApiRsd::class,
  78                 'compare' => ApiComparePages::class,
  79                 'tokens' => ApiTokens::class,
  80                 'checktoken' => ApiCheckToken::class,
  81                 'cspreport' => ApiCSPReport::class,
  82                 'validatepassword' => ApiValidatePassword::class,
  83
  84                 // Write modules
  85                 'purge' => ApiPurge::class,
  86                 'setnotificationtimestamp' => ApiSetNotificationTimestamp::class,
  87                 'rollback' => ApiRollback::class,
  88                 'delete' => ApiDelete::class,
  89                 'undelete' => ApiUndelete::class,
  90                 'protect' => ApiProtect::class,
  91                 'block' => ApiBlock::class,
  92                 'unblock' => ApiUnblock::class,
  93                 'move' => ApiMove::class,
  94                 'edit' => ApiEditPage::class,
  95                 'upload' => ApiUpload::class,
  96                 'filerevert' => ApiFileRevert::class,
  97                 'emailuser' => ApiEmailUser::class,
  98                 'watch' => ApiWatch::class,
  99                 'patrol' => ApiPatrol::class,
 100                 'import' => ApiImport::class,
 101                 'clearhasmsg' => ApiClearHasMsg::class,
 102                 'userrights' => ApiUserrights::class,
 103                 'options' => ApiOptions::class,
 104                 'imagerotate' => ApiImageRotate::class,
 105                 'revisiondelete' => ApiRevisionDelete::class,
 106                 'managetags' => ApiManageTags::class,
 107                 'tag' => ApiTag::class,
 108                 'mergehistory' => ApiMergeHistory::class,
 109                 'setpagelanguage' => ApiSetPageLanguage::class,
 110         ];
 111
 112         /**
 113          * List of available formats: format name => format class
 114          */
 115         private static $Formats = [
 116                 'json' => ApiFormatJson::class,
 117                 'jsonfm' => ApiFormatJson::class,
 118                 'php' => ApiFormatPhp::class,
 119                 'phpfm' => ApiFormatPhp::class,
 120                 'xml' => ApiFormatXml::class,
 121                 'xmlfm' => ApiFormatXml::class,
 122                 'rawfm' => ApiFormatJson::class,
 123                 'none' => ApiFormatNone::class,
 124         ];
 125
 126         /**
 127          * List of user roles that are specifically relevant to the API.
 128          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 129          *                'params' => [ $someVarToSubst ] ],
 130          * ];
 131          */
 132         private static $mRights = [
 133                 'writeapi' => [
 134                         'msg' => 'right-writeapi',
 135                         'params' => []
 136                 ],
 137                 'apihighlimits' => [
 138                         'msg' => 'api-help-right-apihighlimits',
 139                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 140                 ]
 141         ];
 142
 143         /**
 144          * @var ApiFormatBase
 145          */
 146         private $mPrinter;
 147
 148         private $mModuleMgr, $mResult, $mErrorFormatter = null;
 149         /** @var ApiContinuationManager|null */
 150         private $mContinuationManager;
 151         private $mAction;
 152         private $mEnableWrite;
 153         private $mInternalMode, $mSquidMaxage;
 154         /** @var ApiBase */
 155         private $mModule;
 156
 157         private $mCacheMode = 'private';
 158         private $mCacheControl = [];
 159         private $mParamsUsed = [];
 160         private $mParamsSensitive = [];
 161
 162         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 163         private $lacksSameOriginSecurity = null;
 164
 165         /**
 166          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 167          *
 168          * @param IContextSource|WebRequest $context If this is an instance of
 169          *    FauxRequest, errors are thrown and no printing occurs
 170          * @param bool $enableWrite Should be set to true if the api may modify data
 171          */
 172         public function __construct( $context = null, $enableWrite = false ) {
 173                 if ( $context === null ) {
 174                         $context = RequestContext::getMain();
 175                 } elseif ( $context instanceof WebRequest ) {
 176                         // BC for pre-1.19
 177                         $request = $context;
 178                         $context = RequestContext::getMain();
 179                 }
 180                 // We set a derivative context so we can change stuff later
 181                 $this->setContext( new DerivativeContext( $context ) );
 182
 183                 if ( isset( $request ) ) {
 184                         $this->getContext()->setRequest( $request );
 185                 } else {
 186                         $request = $this->getRequest();
 187                 }
 188
 189                 $this->mInternalMode = ( $request instanceof FauxRequest );
 190
 191                 // Special handling for the main module: $parent === $this
 192                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 193
 194                 $config = $this->getConfig();
 195
 196                 if ( !$this->mInternalMode ) {
 197                         // Log if a request with a non-whitelisted Origin header is seen
 198                         // with session cookies.
 199                         $originHeader = $request->getHeader( 'Origin' );
 200                         if ( $originHeader === false ) {
 201                                 $origins = [];
 202                         } else {
 203                                 $originHeader = trim( $originHeader );
 204                                 $origins = preg_split( '/\s+/', $originHeader );
 205                         }
 206                         $sessionCookies = array_intersect(
 207                                 array_keys( $_COOKIE ),
 208                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 209                         );
 210                         if ( $origins && $sessionCookies && (
 211                                 count( $origins ) !== 1 || !self::matchOrigin(
 212                                         $origins[0],
 213                                         $config->get( 'CrossSiteAJAXdomains' ),
 214                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 215                                 )
 216                         ) ) {
 217                                 LoggerFactory::getInstance( 'cors' )->warning(
 218                                         'Non-whitelisted CORS request with session cookies', [
 219                                                 'origin' => $originHeader,
 220                                                 'cookies' => $sessionCookies,
 221                                                 'ip' => $request->getIP(),
 222                                                 'userAgent' => $this->getUserAgent(),
 223                                                 'wiki' => wfWikiID(),
 224                                         ]
 225                                 );
 226                         }
 227
 228                         // If we're in a mode that breaks the same-origin policy, strip
 229                         // user credentials for security.
 230                         if ( $this->lacksSameOriginSecurity() ) {
 231                                 global $wgUser;
 232                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 233                                 $wgUser = new User();
 234                                 $this->getContext()->setUser( $wgUser );
 235                                 $request->response()->header( 'MediaWiki-Login-Suppressed: true' );
 236                         }
 237                 }
 238
 239                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 240
 241                 // Setup uselang. This doesn't use $this->getParameter()
 242                 // because we're not ready to handle errors yet.
 243                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 244                 if ( $uselang === 'user' ) {
 245                         // Assume the parent context is going to return the user language
 246                         // for uselang=user (see T85635).
 247                 } else {
 248                         if ( $uselang === 'content' ) {
 249                                 global $wgContLang;
 250                                 $uselang = $wgContLang->getCode();
 251                         }
 252                         $code = RequestContext::sanitizeLangCode( $uselang );
 253                         $this->getContext()->setLanguage( $code );
 254                         if ( !$this->mInternalMode ) {
 255                                 global $wgLang;
 256                                 $wgLang = $this->getContext()->getLanguage();
 257                                 RequestContext::getMain()->setLanguage( $wgLang );
 258                         }
 259                 }
 260
 261                 // Set up the error formatter. This doesn't use $this->getParameter()
 262                 // because we're not ready to handle errors yet.
 263                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 264                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 265                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 266                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 267                         if ( $errorLangCode === 'uselang' ) {
 268                                 $errorLang = $this->getLanguage();
 269                         } elseif ( $errorLangCode === 'content' ) {
 270                                 global $wgContLang;
 271                                 $errorLang = $wgContLang;
 272                         } else {
 273                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 274                                 $errorLang = Language::factory( $errorLangCode );
 275                         }
 276                         $this->mErrorFormatter = new ApiErrorFormatter(
 277                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 278                         );
 279                 } else {
 280                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 281                 }
 282                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 283
 284                 $this->mModuleMgr = new ApiModuleManager( $this );
 285                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 286                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 287                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 288                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 289
 290                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 291
 292                 $this->mContinuationManager = null;
 293                 $this->mEnableWrite = $enableWrite;
 294
 295                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 296                 $this->mCommit = false;
 297         }
 298
 299         /**
 300          * Return true if the API was started by other PHP code using FauxRequest
 301          * @return bool
 302          */
 303         public function isInternalMode() {
 304                 return $this->mInternalMode;
 305         }
 306
 307         /**
 308          * Get the ApiResult object associated with current request
 309          *
 310          * @return ApiResult
 311          */
 312         public function getResult() {
 313                 return $this->mResult;
 314         }
 315
 316         /**
 317          * Get the security flag for the current request
 318          * @return bool
 319          */
 320         public function lacksSameOriginSecurity() {
 321                 if ( $this->lacksSameOriginSecurity !== null ) {
 322                         return $this->lacksSameOriginSecurity;
 323                 }
 324
 325                 $request = $this->getRequest();
 326
 327                 // JSONP mode
 328                 if ( $request->getVal( 'callback' ) !== null ) {
 329                         $this->lacksSameOriginSecurity = true;
 330                         return true;
 331                 }
 332
 333                 // Anonymous CORS
 334                 if ( $request->getVal( 'origin' ) === '*' ) {
 335                         $this->lacksSameOriginSecurity = true;
 336                         return true;
 337                 }
 338
 339                 // Header to be used from XMLHTTPRequest when the request might
 340                 // otherwise be used for XSS.
 341                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 342                         $this->lacksSameOriginSecurity = true;
 343                         return true;
 344                 }
 345
 346                 // Allow extensions to override.
 347                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 348                 return $this->lacksSameOriginSecurity;
 349         }
 350
 351         /**
 352          * Get the ApiErrorFormatter object associated with current request
 353          * @return ApiErrorFormatter
 354          */
 355         public function getErrorFormatter() {
 356                 return $this->mErrorFormatter;
 357         }
 358
 359         /**
 360          * Get the continuation manager
 361          * @return ApiContinuationManager|null
 362          */
 363         public function getContinuationManager() {
 364                 return $this->mContinuationManager;
 365         }
 366
 367         /**
 368          * Set the continuation manager
 369          * @param ApiContinuationManager|null $manager
 370          */
 371         public function setContinuationManager( $manager ) {
 372                 if ( $manager !== null ) {
 373                         if ( !$manager instanceof ApiContinuationManager ) {
 374                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 375                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 376                                 );
 377                         }
 378                         if ( $this->mContinuationManager !== null ) {
 379                                 throw new UnexpectedValueException(
 380                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 381                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 382                                 );
 383                         }
 384                 }
 385                 $this->mContinuationManager = $manager;
 386         }
 387
 388         /**
 389          * Get the API module object. Only works after executeAction()
 390          *
 391          * @return ApiBase
 392          */
 393         public function getModule() {
 394                 return $this->mModule;
 395         }
 396
 397         /**
 398          * Get the result formatter object. Only works after setupExecuteAction()
 399          *
 400          * @return ApiFormatBase
 401          */
 402         public function getPrinter() {
 403                 return $this->mPrinter;
 404         }
 405
 406         /**
 407          * Set how long the response should be cached.
 408          *
 409          * @param int $maxage
 410          */
 411         public function setCacheMaxAge( $maxage ) {
 412                 $this->setCacheControl( [
 413                         'max-age' => $maxage,
 414                         's-maxage' => $maxage
 415                 ] );
 416         }
 417
 418         /**
 419          * Set the type of caching headers which will be sent.
 420          *
 421          * @param string $mode One of:
 422          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 423          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 424          *         not provided by any of these means, the object will be private.
 425          *    - 'private':    Cache this object only in private client-side caches.
 426          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 427          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 428          *         set consistently for a given URL, it cannot be set differently depending on
 429          *         things like the contents of the database, or whether the user is logged in.
 430          *
 431          *  If the wiki does not allow anonymous users to read it, the mode set here
 432          *  will be ignored, and private caching headers will always be sent. In other words,
 433          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 434          *  view.
 435          *
 436          *  For user-dependent data, the private mode should generally be used. The
 437          *  anon-public-user-private mode should only be used where there is a particularly
 438          *  good performance reason for caching the anonymous response, but where the
 439          *  response to logged-in users may differ, or may contain private data.
 440          *
 441          *  If this function is never called, then the default will be the private mode.
 442          */
 443         public function setCacheMode( $mode ) {
 444                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 445                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 446
 447                         // Ignore for forwards-compatibility
 448                         return;
 449                 }
 450
 451                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 452                         // Private wiki, only private headers
 453                         if ( $mode !== 'private' ) {
 454                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 455
 456                                 return;
 457                         }
 458                 }
 459
 460                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 461                         // User language is used for i18n, so we don't want to publicly
 462                         // cache. Anons are ok, because if they have non-default language
 463                         // then there's an appropriate Vary header set by whatever set
 464                         // their non-default language.
 465                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 466                                 "'anon-public-user-private' due to uselang=user\n" );
 467                         $mode = 'anon-public-user-private';
 468                 }
 469
 470                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 471                 $this->mCacheMode = $mode;
 472         }
 473
 474         /**
 475          * Set directives (key/value pairs) for the Cache-Control header.
 476          * Boolean values will be formatted as such, by including or omitting
 477          * without an equals sign.
 478          *
 479          * Cache control values set here will only be used if the cache mode is not
 480          * private, see setCacheMode().
 481          *
 482          * @param array $directives
 483          */
 484         public function setCacheControl( $directives ) {
 485                 $this->mCacheControl = $directives + $this->mCacheControl;
 486         }
 487
 488         /**
 489          * Create an instance of an output formatter by its name
 490          *
 491          * @param string $format
 492          *
 493          * @return ApiFormatBase
 494          */
 495         public function createPrinterByName( $format ) {
 496                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 497                 if ( $printer === null ) {
 498                         $this->dieWithError(
 499                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 500                         );
 501                 }
 502
 503                 return $printer;
 504         }
 505
 506         /**
 507          * Execute api request. Any errors will be handled if the API was called by the remote client.
 508          */
 509         public function execute() {
 510                 if ( $this->mInternalMode ) {
 511                         $this->executeAction();
 512                 } else {
 513                         $this->executeActionWithErrorHandling();
 514                 }
 515         }
 516
 517         /**
 518          * Execute an action, and in case of an error, erase whatever partial results
 519          * have been accumulated, and replace it with an error message and a help screen.
 520          */
 521         protected function executeActionWithErrorHandling() {
 522                 // Verify the CORS header before executing the action
 523                 if ( !$this->handleCORS() ) {
 524                         // handleCORS() has sent a 403, abort
 525                         return;
 526                 }
 527
 528                 // Exit here if the request method was OPTIONS
 529                 // (assume there will be a followup GET or POST)
 530                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 531                         return;
 532                 }
 533
 534                 // In case an error occurs during data output,
 535                 // clear the output buffer and print just the error information
 536                 $obLevel = ob_get_level();
 537                 ob_start();
 538
 539                 $t = microtime( true );
 540                 $isError = false;
 541                 try {
 542                         $this->executeAction();
 543                         $runTime = microtime( true ) - $t;
 544                         $this->logRequest( $runTime );
 545                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 546                                 MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 547                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 548                                 );
 549                         }
 550                 } catch ( Exception $e ) {
 551                         $this->handleException( $e );
 552                         $this->logRequest( microtime( true ) - $t, $e );
 553                         $isError = true;
 554                 }
 555
 556                 // Commit DBs and send any related cookies and headers
 557                 MediaWiki::preOutputCommit( $this->getContext() );
 558
 559                 // Send cache headers after any code which might generate an error, to
 560                 // avoid sending public cache headers for errors.
 561                 $this->sendCacheHeaders( $isError );
 562
 563                 // Executing the action might have already messed with the output
 564                 // buffers.
 565                 while ( ob_get_level() > $obLevel ) {
 566                         ob_end_flush();
 567                 }
 568         }
 569
 570         /**
 571          * Handle an exception as an API response
 572          *
 573          * @since 1.23
 574          * @param Exception $e
 575          */
 576         protected function handleException( Exception $e ) {
 577                 // T65145: Rollback any open database transactions
 578                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 579                         // UsageExceptions are intentional, so don't rollback if that's the case
 580                         MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 581                 }
 582
 583                 // Allow extra cleanup and logging
 584                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 585
 586                 // Handle any kind of exception by outputting properly formatted error message.
 587                 // If this fails, an unhandled exception should be thrown so that global error
 588                 // handler will process and log it.
 589
 590                 $errCodes = $this->substituteResultWithError( $e );
 591
 592                 // Error results should not be cached
 593                 $this->setCacheMode( 'private' );
 594
 595                 $response = $this->getRequest()->response();
 596                 $headerStr = 'MediaWiki-API-Error: ' . join( ', ', $errCodes );
 597                 $response->header( $headerStr );
 598
 599                 // Reset and print just the error message
 600                 ob_clean();
 601
 602                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 603                 $this->createErrorPrinter();
 604
 605                 $failed = false;
 606                 try {
 607                         $this->printResult( $e->getCode() );
 608                 } catch ( ApiUsageException $ex ) {
 609                         // The error printer itself is failing. Try suppressing its request
 610                         // parameters and redo.
 611                         $failed = true;
 612                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 613                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 614                                 try {
 615                                         $this->mPrinter->addWarning( $error );
 616                                 } catch ( Exception $ex2 ) {
 617                                         // WTF?
 618                                         $this->addWarning( $error );
 619                                 }
 620                         }
 621                 } catch ( UsageException $ex ) {
 622                         // The error printer itself is failing. Try suppressing its request
 623                         // parameters and redo.
 624                         $failed = true;
 625                         $this->addWarning(
 626                                 [ 'apiwarn-errorprinterfailed-ex', $ex->getMessage() ], 'errorprinterfailed'
 627                         );
 628                 }
 629                 if ( $failed ) {
 630                         $this->mPrinter = null;
 631                         $this->createErrorPrinter();
 632                         $this->mPrinter->forceDefaultParams();
 633                         if ( $e->getCode() ) {
 634                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 635                         }
 636                         $this->printResult( $e->getCode() );
 637                 }
 638         }
 639
 640         /**
 641          * Handle an exception from the ApiBeforeMain hook.
 642          *
 643          * This tries to print the exception as an API response, to be more
 644          * friendly to clients. If it fails, it will rethrow the exception.
 645          *
 646          * @since 1.23
 647          * @param Exception $e
 648          * @throws Exception
 649          */
 650         public static function handleApiBeforeMainException( Exception $e ) {
 651                 ob_start();
 652
 653                 try {
 654                         $main = new self( RequestContext::getMain(), false );
 655                         $main->handleException( $e );
 656                         $main->logRequest( 0, $e );
 657                 } catch ( Exception $e2 ) {
 658                         // Nope, even that didn't work. Punt.
 659                         throw $e;
 660                 }
 661
 662                 // Reset cache headers
 663                 $main->sendCacheHeaders( true );
 664
 665                 ob_end_flush();
 666         }
 667
 668         /**
 669          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 670          *
 671          * If no origin parameter is present, nothing happens.
 672          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 673          * is set and false is returned.
 674          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 675          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 676          * headers are set.
 677          * https://www.w3.org/TR/cors/#resource-requests
 678          * https://www.w3.org/TR/cors/#resource-preflight-requests
 679          *
 680          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 681          */
 682         protected function handleCORS() {
 683                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 684                 if ( $originParam === null ) {
 685                         // No origin parameter, nothing to do
 686                         return true;
 687                 }
 688
 689                 $request = $this->getRequest();
 690                 $response = $request->response();
 691
 692                 $matchedOrigin = false;
 693                 $allowTiming = false;
 694                 $varyOrigin = true;
 695
 696                 if ( $originParam === '*' ) {
 697                         // Request for anonymous CORS
 698                         // Technically we should check for the presence of an Origin header
 699                         // and not process it as CORS if it's not set, but that would
 700                         // require us to vary on Origin for all 'origin=*' requests which
 701                         // we don't want to do.
 702                         $matchedOrigin = true;
 703                         $allowOrigin = '*';
 704                         $allowCredentials = 'false';
 705                         $varyOrigin = false; // No need to vary
 706                 } else {
 707                         // Non-anonymous CORS, check we allow the domain
 708
 709                         // Origin: header is a space-separated list of origins, check all of them
 710                         $originHeader = $request->getHeader( 'Origin' );
 711                         if ( $originHeader === false ) {
 712                                 $origins = [];
 713                         } else {
 714                                 $originHeader = trim( $originHeader );
 715                                 $origins = preg_split( '/\s+/', $originHeader );
 716                         }
 717
 718                         if ( !in_array( $originParam, $origins ) ) {
 719                                 // origin parameter set but incorrect
 720                                 // Send a 403 response
 721                                 $response->statusHeader( 403 );
 722                                 $response->header( 'Cache-Control: no-cache' );
 723                                 echo "'origin' parameter does not match Origin header\n";
 724
 725                                 return false;
 726                         }
 727
 728                         $config = $this->getConfig();
 729                         $matchedOrigin = count( $origins ) === 1 && self::matchOrigin(
 730                                 $originParam,
 731                                 $config->get( 'CrossSiteAJAXdomains' ),
 732                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 733                         );
 734
 735                         $allowOrigin = $originHeader;
 736                         $allowCredentials = 'true';
 737                         $allowTiming = $originHeader;
 738                 }
 739
 740                 if ( $matchedOrigin ) {
 741                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 742                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 743                         if ( $preflight ) {
 744                                 // This is a CORS preflight request
 745                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 746                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 747                                         $response->header( 'MediaWiki-CORS-Rejection: Unsupported method requested in preflight' );
 748                                         return true;
 749                                 }
 750                                 // We allow the actual request to send the following headers
 751                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 752                                 if ( $requestedHeaders !== false ) {
 753                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 754                                                 $response->header( 'MediaWiki-CORS-Rejection: Unsupported header requested in preflight' );
 755                                                 return true;
 756                                         }
 757                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 758                                 }
 759
 760                                 // We only allow the actual request to be GET or POST
 761                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 762                         } elseif ( $request->getMethod() !== 'POST' && $request->getMethod() !== 'GET' ) {
 763                                 // Unsupported non-preflight method, don't handle it as CORS
 764                                 $response->header(
 765                                         'MediaWiki-CORS-Rejection: Unsupported method for simple request or actual request'
 766                                 );
 767                                 return true;
 768                         }
 769
 770                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 771                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 772                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 773                         if ( $allowTiming !== false ) {
 774                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 775                         }
 776
 777                         if ( !$preflight ) {
 778                                 $response->header(
 779                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag, '
 780                                         . 'MediaWiki-Login-Suppressed'
 781                                 );
 782                         }
 783                 } else {
 784                         $response->header( 'MediaWiki-CORS-Rejection: Origin mismatch' );
 785                 }
 786
 787                 if ( $varyOrigin ) {
 788                         $this->getOutput()->addVaryHeader( 'Origin' );
 789                 }
 790
 791                 return true;
 792         }
 793
 794         /**
 795          * Attempt to match an Origin header against a set of rules and a set of exceptions
 796          * @param string $value Origin header
 797          * @param array $rules Set of wildcard rules
 798          * @param array $exceptions Set of wildcard rules
 799          * @return bool True if $value matches a rule in $rules and doesn't match
 800          *    any rules in $exceptions, false otherwise
 801          */
 802         protected static function matchOrigin( $value, $rules, $exceptions ) {
 803                 foreach ( $rules as $rule ) {
 804                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 805                                 // Rule matches, check exceptions
 806                                 foreach ( $exceptions as $exc ) {
 807                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 808                                                 return false;
 809                                         }
 810                                 }
 811
 812                                 return true;
 813                         }
 814                 }
 815
 816                 return false;
 817         }
 818
 819         /**
 820          * Attempt to validate the value of Access-Control-Request-Headers against a list
 821          * of headers that we allow the follow up request to send.
 822          *
 823          * @param string $requestedHeaders Comma seperated list of HTTP headers
 824          * @return bool True if all requested headers are in the list of allowed headers
 825          */
 826         protected static function matchRequestedHeaders( $requestedHeaders ) {
 827                 if ( trim( $requestedHeaders ) === '' ) {
 828                         return true;
 829                 }
 830                 $requestedHeaders = explode( ',', $requestedHeaders );
 831                 $allowedAuthorHeaders = array_flip( [
 832                         /* simple headers (see spec) */
 833                         'accept',
 834                         'accept-language',
 835                         'content-language',
 836                         'content-type',
 837                         /* non-authorable headers in XHR, which are however requested by some UAs */
 838                         'accept-encoding',
 839                         'dnt',
 840                         'origin',
 841                         /* MediaWiki whitelist */
 842                         'api-user-agent',
 843                 ] );
 844                 foreach ( $requestedHeaders as $rHeader ) {
 845                         $rHeader = strtolower( trim( $rHeader ) );
 846                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 847                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 848                                 return false;
 849                         }
 850                 }
 851                 return true;
 852         }
 853
 854         /**
 855          * Helper function to convert wildcard string into a regex
 856          * '*' => '.*?'
 857          * '?' => '.'
 858          *
 859          * @param string $wildcard String with wildcards
 860          * @return string Regular expression
 861          */
 862         protected static function wildcardToRegex( $wildcard ) {
 863                 $wildcard = preg_quote( $wildcard, '/' );
 864                 $wildcard = str_replace(
 865                         [ '\*', '\?' ],
 866                         [ '.*?', '.' ],
 867                         $wildcard
 868                 );
 869
 870                 return "/^https?:\/\/$wildcard$/";
 871         }
 872
 873         /**
 874          * Send caching headers
 875          * @param bool $isError Whether an error response is being output
 876          * @since 1.26 added $isError parameter
 877          */
 878         protected function sendCacheHeaders( $isError ) {
 879                 $response = $this->getRequest()->response();
 880                 $out = $this->getOutput();
 881
 882                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 883
 884                 $config = $this->getConfig();
 885
 886                 if ( $config->get( 'VaryOnXFP' ) ) {
 887                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 888                 }
 889
 890                 if ( !$isError && $this->mModule &&
 891                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 892                 ) {
 893                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 894                         if ( $etag !== null ) {
 895                                 $response->header( "ETag: $etag" );
 896                         }
 897                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 898                         if ( $lastMod !== null ) {
 899                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 900                         }
 901                 }
 902
 903                 // The logic should be:
 904                 // $this->mCacheControl['max-age'] is set?
 905                 //    Use it, the module knows better than our guess.
 906                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 907                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 908                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 909                 $maxage = 0;
 910                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 911                         $maxage = $this->mCacheControl['max-age'];
 912                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 913                         $this->mCacheMode !== 'private'
 914                 ) {
 915                         $maxage = $this->getParameter( 'maxage' );
 916                 }
 917                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 918
 919                 if ( $this->mCacheMode == 'private' ) {
 920                         $response->header( "Cache-Control: $privateCache" );
 921                         return;
 922                 }
 923
 924                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 925                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 926                         $out->addVaryHeader( 'Cookie' );
 927                         $response->header( $out->getVaryHeader() );
 928                         if ( $useKeyHeader ) {
 929                                 $response->header( $out->getKeyHeader() );
 930                                 if ( $out->haveCacheVaryCookies() ) {
 931                                         // Logged in, mark this request private
 932                                         $response->header( "Cache-Control: $privateCache" );
 933                                         return;
 934                                 }
 935                                 // Logged out, send normal public headers below
 936                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 937                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 938                                 // Mark request private
 939                                 $response->header( "Cache-Control: $privateCache" );
 940
 941                                 return;
 942                         } // else no Key and anonymous, send public headers below
 943                 }
 944
 945                 // Send public headers
 946                 $response->header( $out->getVaryHeader() );
 947                 if ( $useKeyHeader ) {
 948                         $response->header( $out->getKeyHeader() );
 949                 }
 950
 951                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 952                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 953                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 954                 }
 955                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 956                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 957                 }
 958
 959                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 960                         // Public cache not requested
 961                         // Sending a Vary header in this case is harmless, and protects us
 962                         // against conditional calls of setCacheMaxAge().
 963                         $response->header( "Cache-Control: $privateCache" );
 964
 965                         return;
 966                 }
 967
 968                 $this->mCacheControl['public'] = true;
 969
 970                 // Send an Expires header
 971                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 972                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 973                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 974
 975                 // Construct the Cache-Control header
 976                 $ccHeader = '';
 977                 $separator = '';
 978                 foreach ( $this->mCacheControl as $name => $value ) {
 979                         if ( is_bool( $value ) ) {
 980                                 if ( $value ) {
 981                                         $ccHeader .= $separator . $name;
 982                                         $separator = ', ';
 983                                 }
 984                         } else {
 985                                 $ccHeader .= $separator . "$name=$value";
 986                                 $separator = ', ';
 987                         }
 988                 }
 989
 990                 $response->header( "Cache-Control: $ccHeader" );
 991         }
 992
 993         /**
 994          * Create the printer for error output
 995          */
 996         private function createErrorPrinter() {
 997                 if ( !isset( $this->mPrinter ) ) {
 998                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 999                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
1000                                 $value = self::API_DEFAULT_FORMAT;
1001                         }
1002                         $this->mPrinter = $this->createPrinterByName( $value );
1003                 }
1004
1005                 // Printer may not be able to handle errors. This is particularly
1006                 // likely if the module returns something for getCustomPrinter().
1007                 if ( !$this->mPrinter->canPrintErrors() ) {
1008                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1009                 }
1010         }
1011
1012         /**
1013          * Create an error message for the given exception.
1014          *
1015          * If an ApiUsageException, errors/warnings will be extracted from the
1016          * embedded StatusValue.
1017          *
1018          * If a base UsageException, the getMessageArray() method will be used to
1019          * extract the code and English message for a single error (no warnings).
1020          *
1021          * Any other exception will be returned with a generic code and wrapper
1022          * text around the exception's (presumably English) message as a single
1023          * error (no warnings).
1024          *
1025          * @param Exception $e
1026          * @param string $type 'error' or 'warning'
1027          * @return ApiMessage[]
1028          * @since 1.27
1029          */
1030         protected function errorMessagesFromException( $e, $type = 'error' ) {
1031                 $messages = [];
1032                 if ( $e instanceof ApiUsageException ) {
1033                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1034                                 $messages[] = ApiMessage::create( $error );
1035                         }
1036                 } elseif ( $type !== 'error' ) {
1037                         // None of the rest have any messages for non-error types
1038                 } elseif ( $e instanceof UsageException ) {
1039                         // User entered incorrect parameters - generate error response
1040                         $data = Wikimedia\quietCall( [ $e, 'getMessageArray' ] );
1041                         $code = $data['code'];
1042                         $info = $data['info'];
1043                         unset( $data['code'], $data['info'] );
1044                         $messages[] = new ApiRawMessage( [ '$1', $info ], $code, $data );
1045                 } else {
1046                         // Something is seriously wrong
1047                         $config = $this->getConfig();
1048                         $class = preg_replace( '#^Wikimedia\\\Rdbms\\\#', '', get_class( $e ) );
1049                         $code = 'internal_api_error_' . $class;
1050                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
1051                                 $params = [ 'apierror-databaseerror', WebRequest::getRequestId() ];
1052                         } else {
1053                                 if ( $e instanceof ILocalizedException ) {
1054                                         $msg = $e->getMessageObject();
1055                                 } elseif ( $e instanceof MessageSpecifier ) {
1056                                         $msg = Message::newFromSpecifier( $e );
1057                                 } else {
1058                                         $msg = wfEscapeWikiText( $e->getMessage() );
1059                                 }
1060                                 $params = [ 'apierror-exceptioncaught', WebRequest::getRequestId(), $msg ];
1061                         }
1062                         $messages[] = ApiMessage::create( $params, $code );
1063                 }
1064                 return $messages;
1065         }
1066
1067         /**
1068          * Replace the result data with the information about an exception.
1069          * @param Exception $e
1070          * @return string[] Error codes
1071          */
1072         protected function substituteResultWithError( $e ) {
1073                 $result = $this->getResult();
1074                 $formatter = $this->getErrorFormatter();
1075                 $config = $this->getConfig();
1076                 $errorCodes = [];
1077
1078                 // Remember existing warnings and errors across the reset
1079                 $errors = $result->getResultData( [ 'errors' ] );
1080                 $warnings = $result->getResultData( [ 'warnings' ] );
1081                 $result->reset();
1082                 if ( $warnings !== null ) {
1083                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1084                 }
1085                 if ( $errors !== null ) {
1086                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1087
1088                         // Collect the copied error codes for the return value
1089                         foreach ( $errors as $error ) {
1090                                 if ( isset( $error['code'] ) ) {
1091                                         $errorCodes[$error['code']] = true;
1092                                 }
1093                         }
1094                 }
1095
1096                 // Add errors from the exception
1097                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1098                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1099                         $errorCodes[$msg->getApiCode()] = true;
1100                         $formatter->addError( $modulePath, $msg );
1101                 }
1102                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1103                         $formatter->addWarning( $modulePath, $msg );
1104                 }
1105
1106                 // Add additional data. Path depends on whether we're in BC mode or not.
1107                 // Data depends on the type of exception.
1108                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1109                         $path = [ 'error' ];
1110                 } else {
1111                         $path = null;
1112                 }
1113                 if ( $e instanceof ApiUsageException || $e instanceof UsageException ) {
1114                         $link = wfExpandUrl( wfScript( 'api' ) );
1115                         $result->addContentValue(
1116                                 $path,
1117                                 'docref',
1118                                 trim(
1119                                         $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1120                                         . ' '
1121                                         . $this->msg( 'api-usage-mailinglist-ref' )->inLanguage( $formatter->getLanguage() )->text()
1122                                 )
1123                         );
1124                 } else {
1125                         if ( $config->get( 'ShowExceptionDetails' ) &&
1126                                 ( !$e instanceof DBError || $config->get( 'ShowDBErrorBacktrace' ) )
1127                         ) {
1128                                 $result->addContentValue(
1129                                         $path,
1130                                         'trace',
1131                                         $this->msg( 'api-exception-trace',
1132                                                 get_class( $e ),
1133                                                 $e->getFile(),
1134                                                 $e->getLine(),
1135                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1136                                         )->inLanguage( $formatter->getLanguage() )->text()
1137                                 );
1138                         }
1139                 }
1140
1141                 // Add the id and such
1142                 $this->addRequestedFields( [ 'servedby' ] );
1143
1144                 return array_keys( $errorCodes );
1145         }
1146
1147         /**
1148          * Add requested fields to the result
1149          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1150          *  - servedby
1151          */
1152         protected function addRequestedFields( $force = [] ) {
1153                 $result = $this->getResult();
1154
1155                 $requestid = $this->getParameter( 'requestid' );
1156                 if ( $requestid !== null ) {
1157                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1158                 }
1159
1160                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1161                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1162                 ) ) {
1163                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1164                 }
1165
1166                 if ( $this->getParameter( 'curtimestamp' ) ) {
1167                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1168                                 ApiResult::NO_SIZE_CHECK );
1169                 }
1170
1171                 if ( $this->getParameter( 'responselanginfo' ) ) {
1172                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1173                                 ApiResult::NO_SIZE_CHECK );
1174                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1175                                 ApiResult::NO_SIZE_CHECK );
1176                 }
1177         }
1178
1179         /**
1180          * Set up for the execution.
1181          * @return array
1182          */
1183         protected function setupExecuteAction() {
1184                 $this->addRequestedFields();
1185
1186                 $params = $this->extractRequestParams();
1187                 $this->mAction = $params['action'];
1188
1189                 return $params;
1190         }
1191
1192         /**
1193          * Set up the module for response
1194          * @return ApiBase The module that will handle this action
1195          * @throws MWException
1196          * @throws ApiUsageException
1197          */
1198         protected function setupModule() {
1199                 // Instantiate the module requested by the user
1200                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1201                 if ( $module === null ) {
1202                         $this->dieWithError(
1203                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1204                         );
1205                 }
1206                 $moduleParams = $module->extractRequestParams();
1207
1208                 // Check token, if necessary
1209                 if ( $module->needsToken() === true ) {
1210                         throw new MWException(
1211                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1212                                 'See documentation for ApiBase::needsToken for details.'
1213                         );
1214                 }
1215                 if ( $module->needsToken() ) {
1216                         if ( !$module->mustBePosted() ) {
1217                                 throw new MWException(
1218                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1219                                 );
1220                         }
1221
1222                         if ( !isset( $moduleParams['token'] ) ) {
1223                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1224                         }
1225
1226                         $module->requirePostedParameters( [ 'token' ] );
1227
1228                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1229                                 $module->dieWithError( 'apierror-badtoken' );
1230                         }
1231                 }
1232
1233                 return $module;
1234         }
1235
1236         /**
1237          * @return array
1238          */
1239         private function getMaxLag() {
1240                 $dbLag = MediaWikiServices::getInstance()->getDBLoadBalancer()->getMaxLag();
1241                 $lagInfo = [
1242                         'host' => $dbLag[0],
1243                         'lag' => $dbLag[1],
1244                         'type' => 'db'
1245                 ];
1246
1247                 $jobQueueLagFactor = $this->getConfig()->get( 'JobQueueIncludeInMaxLagFactor' );
1248                 if ( $jobQueueLagFactor ) {
1249                         // Turn total number of jobs into seconds by using the configured value
1250                         $totalJobs = array_sum( JobQueueGroup::singleton()->getQueueSizes() );
1251                         $jobQueueLag = $totalJobs / (float)$jobQueueLagFactor;
1252                         if ( $jobQueueLag > $lagInfo['lag'] ) {
1253                                 $lagInfo = [
1254                                         'host' => wfHostname(), // XXX: Is there a better value that could be used?
1255                                         'lag' => $jobQueueLag,
1256                                         'type' => 'jobqueue',
1257                                         'jobs' => $totalJobs,
1258                                 ];
1259                         }
1260                 }
1261
1262                 return $lagInfo;
1263         }
1264
1265         /**
1266          * Check the max lag if necessary
1267          * @param ApiBase $module Api module being used
1268          * @param array $params Array an array containing the request parameters.
1269          * @return bool True on success, false should exit immediately
1270          */
1271         protected function checkMaxLag( $module, $params ) {
1272                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1273                         $maxLag = $params['maxlag'];
1274                         $lagInfo = $this->getMaxLag();
1275                         if ( $lagInfo['lag'] > $maxLag ) {
1276                                 $response = $this->getRequest()->response();
1277
1278                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1279                                 $response->header( 'X-Database-Lag: ' . intval( $lagInfo['lag'] ) );
1280
1281                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1282                                         $this->dieWithError(
1283                                                 [ 'apierror-maxlag', $lagInfo['lag'], $lagInfo['host'] ],
1284                                                 'maxlag',
1285                                                 $lagInfo
1286                                         );
1287                                 }
1288
1289                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lagInfo['lag'] ], 'maxlag', $lagInfo );
1290                         }
1291                 }
1292
1293                 return true;
1294         }
1295
1296         /**
1297          * Check selected RFC 7232 precondition headers
1298          *
1299          * RFC 7232 envisions a particular model where you send your request to "a
1300          * resource", and for write requests that you can read "the resource" by
1301          * changing the method to GET. When the API receives a GET request, it
1302          * works out even though "the resource" from RFC 7232's perspective might
1303          * be many resources from MediaWiki's perspective. But it totally fails for
1304          * a POST, since what HTTP sees as "the resource" is probably just
1305          * "/api.php" with all the interesting bits in the body.
1306          *
1307          * Therefore, we only support RFC 7232 precondition headers for GET (and
1308          * HEAD). That means we don't need to bother with If-Match and
1309          * If-Unmodified-Since since they only apply to modification requests.
1310          *
1311          * And since we don't support Range, If-Range is ignored too.
1312          *
1313          * @since 1.26
1314          * @param ApiBase $module Api module being used
1315          * @return bool True on success, false should exit immediately
1316          */
1317         protected function checkConditionalRequestHeaders( $module ) {
1318                 if ( $this->mInternalMode ) {
1319                         // No headers to check in internal mode
1320                         return true;
1321                 }
1322
1323                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1324                         // Don't check POSTs
1325                         return true;
1326                 }
1327
1328                 $return304 = false;
1329
1330                 $ifNoneMatch = array_diff(
1331                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1332                         [ '' ]
1333                 );
1334                 if ( $ifNoneMatch ) {
1335                         if ( $ifNoneMatch === [ '*' ] ) {
1336                                 // API responses always "exist"
1337                                 $etag = '*';
1338                         } else {
1339                                 $etag = $module->getConditionalRequestData( 'etag' );
1340                         }
1341                 }
1342                 if ( $ifNoneMatch && $etag !== null ) {
1343                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1344                         $match = array_map( function ( $s ) {
1345                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1346                         }, $ifNoneMatch );
1347                         $return304 = in_array( $test, $match, true );
1348                 } else {
1349                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1350
1351                         // Some old browsers sends sizes after the date, like this:
1352                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1353                         // Ignore that.
1354                         $i = strpos( $value, ';' );
1355                         if ( $i !== false ) {
1356                                 $value = trim( substr( $value, 0, $i ) );
1357                         }
1358
1359                         if ( $value !== '' ) {
1360                                 try {
1361                                         $ts = new MWTimestamp( $value );
1362                                         if (
1363                                                 // RFC 7231 IMF-fixdate
1364                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1365                                                 // RFC 850
1366                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1367                                                 // asctime (with and without space-padded day)
1368                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1369                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1370                                         ) {
1371                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1372                                                 if ( $lastMod !== null ) {
1373                                                         // Mix in some MediaWiki modification times
1374                                                         $modifiedTimes = [
1375                                                                 'page' => $lastMod,
1376                                                                 'user' => $this->getUser()->getTouched(),
1377                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1378                                                         ];
1379                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1380                                                                 // T46570: the core page itself may not change, but resources might
1381                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1382                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1383                                                                 );
1384                                                         }
1385                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1386                                                         $lastMod = max( $modifiedTimes );
1387                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1388                                                 }
1389                                         }
1390                                 } catch ( TimestampException $e ) {
1391                                         // Invalid timestamp, ignore it
1392                                 }
1393                         }
1394                 }
1395
1396                 if ( $return304 ) {
1397                         $this->getRequest()->response()->statusHeader( 304 );
1398
1399                         // Avoid outputting the compressed representation of a zero-length body
1400                         Wikimedia\suppressWarnings();
1401                         ini_set( 'zlib.output_compression', 0 );
1402                         Wikimedia\restoreWarnings();
1403                         wfClearOutputBuffers();
1404
1405                         return false;
1406                 }
1407
1408                 return true;
1409         }
1410
1411         /**
1412          * Check for sufficient permissions to execute
1413          * @param ApiBase $module An Api module
1414          */
1415         protected function checkExecutePermissions( $module ) {
1416                 $user = $this->getUser();
1417                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1418                         !$user->isAllowed( 'read' )
1419                 ) {
1420                         $this->dieWithError( 'apierror-readapidenied' );
1421                 }
1422
1423                 if ( $module->isWriteMode() ) {
1424                         if ( !$this->mEnableWrite ) {
1425                                 $this->dieWithError( 'apierror-noapiwrite' );
1426                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1427                                 $this->dieWithError( 'apierror-writeapidenied' );
1428                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1429                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1430                         }
1431
1432                         $this->checkReadOnly( $module );
1433                 }
1434
1435                 // Allow extensions to stop execution for arbitrary reasons.
1436                 $message = false;
1437                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1438                         $this->dieWithError( $message );
1439                 }
1440         }
1441
1442         /**
1443          * Check if the DB is read-only for this user
1444          * @param ApiBase $module An Api module
1445          */
1446         protected function checkReadOnly( $module ) {
1447                 if ( wfReadOnly() ) {
1448                         $this->dieReadOnly();
1449                 }
1450
1451                 if ( $module->isWriteMode()
1452                         && $this->getUser()->isBot()
1453                         && MediaWikiServices::getInstance()->getDBLoadBalancer()->getServerCount() > 1
1454                 ) {
1455                         $this->checkBotReadOnly();
1456                 }
1457         }
1458
1459         /**
1460          * Check whether we are readonly for bots
1461          */
1462         private function checkBotReadOnly() {
1463                 // Figure out how many servers have passed the lag threshold
1464                 $numLagged = 0;
1465                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1466                 $laggedServers = [];
1467                 $loadBalancer = MediaWikiServices::getInstance()->getDBLoadBalancer();
1468                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1469                         if ( $lag > $lagLimit ) {
1470                                 ++$numLagged;
1471                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1472                         }
1473                 }
1474
1475                 // If a majority of replica DBs are too lagged then disallow writes
1476                 $replicaCount = $loadBalancer->getServerCount() - 1;
1477                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1478                         $laggedServers = implode( ', ', $laggedServers );
1479                         wfDebugLog(
1480                                 'api-readonly',
1481                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1482                         );
1483
1484                         $this->dieWithError(
1485                                 'readonly_lag',
1486                                 'readonly',
1487                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1488                         );
1489                 }
1490         }
1491
1492         /**
1493          * Check asserts of the user's rights
1494          * @param array $params
1495          */
1496         protected function checkAsserts( $params ) {
1497                 if ( isset( $params['assert'] ) ) {
1498                         $user = $this->getUser();
1499                         switch ( $params['assert'] ) {
1500                                 case 'user':
1501                                         if ( $user->isAnon() ) {
1502                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1503                                         }
1504                                         break;
1505                                 case 'bot':
1506                                         if ( !$user->isAllowed( 'bot' ) ) {
1507                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1508                                         }
1509                                         break;
1510                         }
1511                 }
1512                 if ( isset( $params['assertuser'] ) ) {
1513                         $assertUser = User::newFromName( $params['assertuser'], false );
1514                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1515                                 $this->dieWithError(
1516                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1517                                 );
1518                         }
1519                 }
1520         }
1521
1522         /**
1523          * Check POST for external response and setup result printer
1524          * @param ApiBase $module An Api module
1525          * @param array $params An array with the request parameters
1526          */
1527         protected function setupExternalResponse( $module, $params ) {
1528                 $request = $this->getRequest();
1529                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1530                         // Module requires POST. GET request might still be allowed
1531                         // if $wgDebugApi is true, otherwise fail.
1532                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1533                 }
1534
1535                 // See if custom printer is used
1536                 $this->mPrinter = $module->getCustomPrinter();
1537                 if ( is_null( $this->mPrinter ) ) {
1538                         // Create an appropriate printer
1539                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1540                 }
1541
1542                 if ( $request->getProtocol() === 'http' && (
1543                         $request->getSession()->shouldForceHTTPS() ||
1544                         ( $this->getUser()->isLoggedIn() &&
1545                                 $this->getUser()->requiresHTTPS() )
1546                 ) ) {
1547                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1548                 }
1549         }
1550
1551         /**
1552          * Execute the actual module, without any error handling
1553          */
1554         protected function executeAction() {
1555                 $params = $this->setupExecuteAction();
1556                 $module = $this->setupModule();
1557                 $this->mModule = $module;
1558
1559                 if ( !$this->mInternalMode ) {
1560                         $this->setRequestExpectations( $module );
1561                 }
1562
1563                 $this->checkExecutePermissions( $module );
1564
1565                 if ( !$this->checkMaxLag( $module, $params ) ) {
1566                         return;
1567                 }
1568
1569                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1570                         return;
1571                 }
1572
1573                 if ( !$this->mInternalMode ) {
1574                         $this->setupExternalResponse( $module, $params );
1575                 }
1576
1577                 $this->checkAsserts( $params );
1578
1579                 // Execute
1580                 $module->execute();
1581                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1582
1583                 $this->reportUnusedParams();
1584
1585                 if ( !$this->mInternalMode ) {
1586                         // append Debug information
1587                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1588
1589                         // Print result data
1590                         $this->printResult();
1591                 }
1592         }
1593
1594         /**
1595          * Set database connection, query, and write expectations given this module request
1596          * @param ApiBase $module
1597          */
1598         protected function setRequestExpectations( ApiBase $module ) {
1599                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1600                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1601                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1602                 if ( $this->getRequest()->hasSafeMethod() ) {
1603                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1604                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1605                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1606                         $this->getRequest()->markAsSafeRequest();
1607                 } else {
1608                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1609                 }
1610         }
1611
1612         /**
1613          * Log the preceding request
1614          * @param float $time Time in seconds
1615          * @param Exception $e Exception caught while processing the request
1616          */
1617         protected function logRequest( $time, $e = null ) {
1618                 $request = $this->getRequest();
1619                 $logCtx = [
1620                         'ts' => time(),
1621                         'ip' => $request->getIP(),
1622                         'userAgent' => $this->getUserAgent(),
1623                         'wiki' => wfWikiID(),
1624                         'timeSpentBackend' => (int)round( $time * 1000 ),
1625                         'hadError' => $e !== null,
1626                         'errorCodes' => [],
1627                         'params' => [],
1628                 ];
1629
1630                 if ( $e ) {
1631                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1632                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1633                         }
1634                 }
1635
1636                 // Construct space separated message for 'api' log channel
1637                 $msg = "API {$request->getMethod()} " .
1638                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1639                         " {$logCtx['ip']} " .
1640                         "T={$logCtx['timeSpentBackend']}ms";
1641
1642                 $sensitive = array_flip( $this->getSensitiveParams() );
1643                 foreach ( $this->getParamsUsed() as $name ) {
1644                         $value = $request->getVal( $name );
1645                         if ( $value === null ) {
1646                                 continue;
1647                         }
1648
1649                         if ( isset( $sensitive[$name] ) ) {
1650                                 $value = '[redacted]';
1651                                 $encValue = '[redacted]';
1652                         } elseif ( strlen( $value ) > 256 ) {
1653                                 $value = substr( $value, 0, 256 );
1654                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1655                         } else {
1656                                 $encValue = $this->encodeRequestLogValue( $value );
1657                         }
1658
1659                         $logCtx['params'][$name] = $value;
1660                         $msg .= " {$name}={$encValue}";
1661                 }
1662
1663                 wfDebugLog( 'api', $msg, 'private' );
1664                 // ApiAction channel is for structured data consumers
1665                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1666         }
1667
1668         /**
1669          * Encode a value in a format suitable for a space-separated log line.
1670          * @param string $s
1671          * @return string
1672          */
1673         protected function encodeRequestLogValue( $s ) {
1674                 static $table;
1675                 if ( !$table ) {
1676                         $chars = ';@$!*(),/:';
1677                         $numChars = strlen( $chars );
1678                         for ( $i = 0; $i < $numChars; $i++ ) {
1679                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1680                         }
1681                 }
1682
1683                 return strtr( rawurlencode( $s ), $table );
1684         }
1685
1686         /**
1687          * Get the request parameters used in the course of the preceding execute() request
1688          * @return array
1689          */
1690         protected function getParamsUsed() {
1691                 return array_keys( $this->mParamsUsed );
1692         }
1693
1694         /**
1695          * Mark parameters as used
1696          * @param string|string[] $params
1697          */
1698         public function markParamsUsed( $params ) {
1699                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1700         }
1701
1702         /**
1703          * Get the request parameters that should be considered sensitive
1704          * @since 1.29
1705          * @return array
1706          */
1707         protected function getSensitiveParams() {
1708                 return array_keys( $this->mParamsSensitive );
1709         }
1710
1711         /**
1712          * Mark parameters as sensitive
1713          * @since 1.29
1714          * @param string|string[] $params
1715          */
1716         public function markParamsSensitive( $params ) {
1717                 $this->mParamsSensitive += array_fill_keys( (array)$params, true );
1718         }
1719
1720         /**
1721          * Get a request value, and register the fact that it was used, for logging.
1722          * @param string $name
1723          * @param mixed $default
1724          * @return mixed
1725          */
1726         public function getVal( $name, $default = null ) {
1727                 $this->mParamsUsed[$name] = true;
1728
1729                 $ret = $this->getRequest()->getVal( $name );
1730                 if ( $ret === null ) {
1731                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1732                                 // See T12262 for why we don't just implode( '|', ... ) the
1733                                 // array.
1734                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1735                         }
1736                         $ret = $default;
1737                 }
1738                 return $ret;
1739         }
1740
1741         /**
1742          * Get a boolean request value, and register the fact that the parameter
1743          * was used, for logging.
1744          * @param string $name
1745          * @return bool
1746          */
1747         public function getCheck( $name ) {
1748                 return $this->getVal( $name, null ) !== null;
1749         }
1750
1751         /**
1752          * Get a request upload, and register the fact that it was used, for logging.
1753          *
1754          * @since 1.21
1755          * @param string $name Parameter name
1756          * @return WebRequestUpload
1757          */
1758         public function getUpload( $name ) {
1759                 $this->mParamsUsed[$name] = true;
1760
1761                 return $this->getRequest()->getUpload( $name );
1762         }
1763
1764         /**
1765          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1766          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1767          */
1768         protected function reportUnusedParams() {
1769                 $paramsUsed = $this->getParamsUsed();
1770                 $allParams = $this->getRequest()->getValueNames();
1771
1772                 if ( !$this->mInternalMode ) {
1773                         // Printer has not yet executed; don't warn that its parameters are unused
1774                         $printerParams = $this->mPrinter->encodeParamName(
1775                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1776                         );
1777                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1778                 } else {
1779                         $unusedParams = array_diff( $allParams, $paramsUsed );
1780                 }
1781
1782                 if ( count( $unusedParams ) ) {
1783                         $this->addWarning( [
1784                                 'apierror-unrecognizedparams',
1785                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1786                                 count( $unusedParams )
1787                         ] );
1788                 }
1789         }
1790
1791         /**
1792          * Print results using the current printer
1793          *
1794          * @param int $httpCode HTTP status code, or 0 to not change
1795          */
1796         protected function printResult( $httpCode = 0 ) {
1797                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1798                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1799                 }
1800
1801                 $printer = $this->mPrinter;
1802                 $printer->initPrinter( false );
1803                 if ( $httpCode ) {
1804                         $printer->setHttpStatus( $httpCode );
1805                 }
1806                 $printer->execute();
1807                 $printer->closePrinter();
1808         }
1809
1810         /**
1811          * @return bool
1812          */
1813         public function isReadMode() {
1814                 return false;
1815         }
1816
1817         /**
1818          * See ApiBase for description.
1819          *
1820          * @return array
1821          */
1822         public function getAllowedParams() {
1823                 return [
1824                         'action' => [
1825                                 ApiBase::PARAM_DFLT => 'help',
1826                                 ApiBase::PARAM_TYPE => 'submodule',
1827                         ],
1828                         'format' => [
1829                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_FORMAT,
1830                                 ApiBase::PARAM_TYPE => 'submodule',
1831                         ],
1832                         'maxlag' => [
1833                                 ApiBase::PARAM_TYPE => 'integer'
1834                         ],
1835                         'smaxage' => [
1836                                 ApiBase::PARAM_TYPE => 'integer',
1837                                 ApiBase::PARAM_DFLT => 0
1838                         ],
1839                         'maxage' => [
1840                                 ApiBase::PARAM_TYPE => 'integer',
1841                                 ApiBase::PARAM_DFLT => 0
1842                         ],
1843                         'assert' => [
1844                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1845                         ],
1846                         'assertuser' => [
1847                                 ApiBase::PARAM_TYPE => 'user',
1848                         ],
1849                         'requestid' => null,
1850                         'servedby' => false,
1851                         'curtimestamp' => false,
1852                         'responselanginfo' => false,
1853                         'origin' => null,
1854                         'uselang' => [
1855                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1856                         ],
1857                         'errorformat' => [
1858                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1859                                 ApiBase::PARAM_DFLT => 'bc',
1860                         ],
1861                         'errorlang' => [
1862                                 ApiBase::PARAM_DFLT => 'uselang',
1863                         ],
1864                         'errorsuselocal' => [
1865                                 ApiBase::PARAM_DFLT => false,
1866                         ],
1867                 ];
1868         }
1869
1870         /** @inheritDoc */
1871         protected function getExamplesMessages() {
1872                 return [
1873                         'action=help'
1874                                 => 'apihelp-help-example-main',
1875                         'action=help&recursivesubmodules=1'
1876                                 => 'apihelp-help-example-recursive',
1877                 ];
1878         }
1879
1880         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1881                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1882                 // reindex the array to get 'permissions' in the right place.
1883                 $oldHelp = $help;
1884                 $help = [];
1885                 foreach ( $oldHelp as $k => $v ) {
1886                         if ( $k === 'submodules' ) {
1887                                 $help['permissions'] = '';
1888                         }
1889                         $help[$k] = $v;
1890                 }
1891                 $help['datatypes'] = '';
1892                 $help['credits'] = '';
1893
1894                 // Fill 'permissions'
1895                 $help['permissions'] .= Html::openElement( 'div',
1896                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1897                 $m = $this->msg( 'api-help-permissions' );
1898                 if ( !$m->isDisabled() ) {
1899                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1900                                 $m->numParams( count( self::$mRights ) )->parse()
1901                         );
1902                 }
1903                 $help['permissions'] .= Html::openElement( 'dl' );
1904                 foreach ( self::$mRights as $right => $rightMsg ) {
1905                         $help['permissions'] .= Html::element( 'dt', null, $right );
1906
1907                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1908                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1909
1910                         $groups = array_map( function ( $group ) {
1911                                 return $group == '*' ? 'all' : $group;
1912                         }, User::getGroupsWithPermission( $right ) );
1913
1914                         $help['permissions'] .= Html::rawElement( 'dd', null,
1915                                 $this->msg( 'api-help-permissions-granted-to' )
1916                                         ->numParams( count( $groups ) )
1917                                         ->params( Message::listParam( $groups ) )
1918                                         ->parse()
1919                         );
1920                 }
1921                 $help['permissions'] .= Html::closeElement( 'dl' );
1922                 $help['permissions'] .= Html::closeElement( 'div' );
1923
1924                 // Fill 'datatypes' and 'credits', if applicable
1925                 if ( empty( $options['nolead'] ) ) {
1926                         $level = $options['headerlevel'];
1927                         $tocnumber = &$options['tocnumber'];
1928
1929                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1930
1931                         $id = Sanitizer::escapeIdForAttribute( 'main/datatypes', Sanitizer::ID_PRIMARY );
1932                         $idFallback = Sanitizer::escapeIdForAttribute( 'main/datatypes', Sanitizer::ID_FALLBACK );
1933                         $headline = Linker::makeHeadline( min( 6, $level ),
1934                                 ' class="apihelp-header">',
1935                                 $id,
1936                                 $header,
1937                                 '',
1938                                 $idFallback
1939                         );
1940                         // Ensure we have a sane anchor
1941                         if ( $id !== 'main/datatypes' && $idFallback !== 'main/datatypes' ) {
1942                                 $headline = '<div id="main/datatypes"></div>' . $headline;
1943                         }
1944                         $help['datatypes'] .= $headline;
1945                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1946                         if ( !isset( $tocData['main/datatypes'] ) ) {
1947                                 $tocnumber[$level]++;
1948                                 $tocData['main/datatypes'] = [
1949                                         'toclevel' => count( $tocnumber ),
1950                                         'level' => $level,
1951                                         'anchor' => 'main/datatypes',
1952                                         'line' => $header,
1953                                         'number' => implode( '.', $tocnumber ),
1954                                         'index' => false,
1955                                 ];
1956                         }
1957
1958                         $header = $this->msg( 'api-credits-header' )->parse();
1959                         $id = Sanitizer::escapeIdForAttribute( 'main/credits', Sanitizer::ID_PRIMARY );
1960                         $idFallback = Sanitizer::escapeIdForAttribute( 'main/credits', Sanitizer::ID_FALLBACK );
1961                         $headline = Linker::makeHeadline( min( 6, $level ),
1962                                 ' class="apihelp-header">',
1963                                 $id,
1964                                 $header,
1965                                 '',
1966                                 $idFallback
1967                         );
1968                         // Ensure we have a sane anchor
1969                         if ( $id !== 'main/credits' && $idFallback !== 'main/credits' ) {
1970                                 $headline = '<div id="main/credits"></div>' . $headline;
1971                         }
1972                         $help['credits'] .= $headline;
1973                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1974                         if ( !isset( $tocData['main/credits'] ) ) {
1975                                 $tocnumber[$level]++;
1976                                 $tocData['main/credits'] = [
1977                                         'toclevel' => count( $tocnumber ),
1978                                         'level' => $level,
1979                                         'anchor' => 'main/credits',
1980                                         'line' => $header,
1981                                         'number' => implode( '.', $tocnumber ),
1982                                         'index' => false,
1983                                 ];
1984                         }
1985                 }
1986         }
1987
1988         private $mCanApiHighLimits = null;
1989
1990         /**
1991          * Check whether the current user is allowed to use high limits
1992          * @return bool
1993          */
1994         public function canApiHighLimits() {
1995                 if ( !isset( $this->mCanApiHighLimits ) ) {
1996                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1997                 }
1998
1999                 return $this->mCanApiHighLimits;
2000         }
2001
2002         /**
2003          * Overrides to return this instance's module manager.
2004          * @return ApiModuleManager
2005          */
2006         public function getModuleManager() {
2007                 return $this->mModuleMgr;
2008         }
2009
2010         /**
2011          * Fetches the user agent used for this request
2012          *
2013          * The value will be the combination of the 'Api-User-Agent' header (if
2014          * any) and the standard User-Agent header (if any).
2015          *
2016          * @return string
2017          */
2018         public function getUserAgent() {
2019                 return trim(
2020                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
2021                         $this->getRequest()->getHeader( 'User-agent' )
2022                 );
2023         }
2024 }
2025
2026 /**
2027  * For really cool vim folding this needs to be at the end:
2028  * vim: foldmarker=@{,@} foldmethod=marker
2029  */