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