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
  28 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42         /**
  43          * When no format parameter is given, this format will be used
  44          */
  45         const API_DEFAULT_FORMAT = 'jsonfm';
  46
  47         /**
  48          * When no uselang parameter is given, this language will be used
  49          */
  50         const API_DEFAULT_USELANG = 'user';
  51
  52         /**
  53          * List of available modules: action name => module class
  54          */
  55         private static $Modules = [
  56                 'login' => ApiLogin::class,
  57                 'clientlogin' => ApiClientLogin::class,
  58                 'logout' => ApiLogout::class,
  59                 'createaccount' => ApiAMCreateAccount::class,
  60                 'linkaccount' => ApiLinkAccount::class,
  61                 'unlinkaccount' => ApiRemoveAuthenticationData::class,
  62                 'changeauthenticationdata' => ApiChangeAuthenticationData::class,
  63                 'removeauthenticationdata' => ApiRemoveAuthenticationData::class,
  64                 'resetpassword' => ApiResetPassword::class,
  65                 'query' => ApiQuery::class,
  66                 'expandtemplates' => ApiExpandTemplates::class,
  67                 'parse' => ApiParse::class,
  68                 'stashedit' => ApiStashEdit::class,
  69                 'opensearch' => ApiOpenSearch::class,
  70                 'feedcontributions' => ApiFeedContributions::class,
  71                 'feedrecentchanges' => ApiFeedRecentChanges::class,
  72                 'feedwatchlist' => ApiFeedWatchlist::class,
  73                 'help' => ApiHelp::class,
  74                 'paraminfo' => ApiParamInfo::class,
  75                 'rsd' => ApiRsd::class,
  76                 'compare' => ApiComparePages::class,
  77                 'tokens' => ApiTokens::class,
  78                 'checktoken' => ApiCheckToken::class,
  79                 'cspreport' => ApiCSPReport::class,
  80                 'validatepassword' => ApiValidatePassword::class,
  81
  82                 // Write modules
  83                 'purge' => ApiPurge::class,
  84                 'setnotificationtimestamp' => ApiSetNotificationTimestamp::class,
  85                 'rollback' => ApiRollback::class,
  86                 'delete' => ApiDelete::class,
  87                 'undelete' => ApiUndelete::class,
  88                 'protect' => ApiProtect::class,
  89                 'block' => ApiBlock::class,
  90                 'unblock' => ApiUnblock::class,
  91                 'move' => ApiMove::class,
  92                 'edit' => ApiEditPage::class,
  93                 'upload' => ApiUpload::class,
  94                 'filerevert' => ApiFileRevert::class,
  95                 'emailuser' => ApiEmailUser::class,
  96                 'watch' => ApiWatch::class,
  97                 'patrol' => ApiPatrol::class,
  98                 'import' => ApiImport::class,
  99                 'clearhasmsg' => ApiClearHasMsg::class,
 100                 'userrights' => ApiUserrights::class,
 101                 'options' => ApiOptions::class,
 102                 'imagerotate' => ApiImageRotate::class,
 103                 'revisiondelete' => ApiRevisionDelete::class,
 104                 'managetags' => ApiManageTags::class,
 105                 'tag' => ApiTag::class,
 106                 'mergehistory' => ApiMergeHistory::class,
 107                 'setpagelanguage' => ApiSetPageLanguage::class,
 108         ];
 109
 110         /**
 111          * List of available formats: format name => format class
 112          */
 113         private static $Formats = [
 114                 'json' => ApiFormatJson::class,
 115                 'jsonfm' => ApiFormatJson::class,
 116                 'php' => ApiFormatPhp::class,
 117                 'phpfm' => ApiFormatPhp::class,
 118                 'xml' => ApiFormatXml::class,
 119                 'xmlfm' => ApiFormatXml::class,
 120                 'rawfm' => ApiFormatJson::class,
 121                 'none' => ApiFormatNone::class,
 122         ];
 123
 124         /**
 125          * List of user roles that are specifically relevant to the API.
 126          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 127          *                'params' => [ $someVarToSubst ] ],
 128          * ];
 129          */
 130         private static $mRights = [
 131                 'writeapi' => [
 132                         'msg' => 'right-writeapi',
 133                         'params' => []
 134                 ],
 135                 'apihighlimits' => [
 136                         'msg' => 'api-help-right-apihighlimits',
 137                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 138                 ]
 139         ];
 140
 141         /**
 142          * @var ApiFormatBase
 143          */
 144         private $mPrinter;
 145
 146         private $mModuleMgr, $mResult, $mErrorFormatter = null;
 147         /** @var ApiContinuationManager|null */
 148         private $mContinuationManager;
 149         private $mAction;
 150         private $mEnableWrite;
 151         private $mInternalMode, $mSquidMaxage;
 152         /** @var ApiBase */
 153         private $mModule;
 154
 155         private $mCacheMode = 'private';
 156         private $mCacheControl = [];
 157         private $mParamsUsed = [];
 158         private $mParamsSensitive = [];
 159
 160         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 161         private $lacksSameOriginSecurity = null;
 162
 163         /**
 164          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 165          *
 166          * @param IContextSource|WebRequest|null $context If this is an instance of
 167          *    FauxRequest, errors are thrown and no printing occurs
 168          * @param bool $enableWrite Should be set to true if the api may modify data
 169          */
 170         public function __construct( $context = null, $enableWrite = false ) {
 171                 if ( $context === null ) {
 172                         $context = RequestContext::getMain();
 173                 } elseif ( $context instanceof WebRequest ) {
 174                         // BC for pre-1.19
 175                         $request = $context;
 176                         $context = RequestContext::getMain();
 177                 }
 178                 // We set a derivative context so we can change stuff later
 179                 $this->setContext( new DerivativeContext( $context ) );
 180
 181                 if ( isset( $request ) ) {
 182                         $this->getContext()->setRequest( $request );
 183                 } else {
 184                         $request = $this->getRequest();
 185                 }
 186
 187                 $this->mInternalMode = ( $request instanceof FauxRequest );
 188
 189                 // Special handling for the main module: $parent === $this
 190                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 191
 192                 $config = $this->getConfig();
 193
 194                 if ( !$this->mInternalMode ) {
 195                         // Log if a request with a non-whitelisted Origin header is seen
 196                         // with session cookies.
 197                         $originHeader = $request->getHeader( 'Origin' );
 198                         if ( $originHeader === false ) {
 199                                 $origins = [];
 200                         } else {
 201                                 $originHeader = trim( $originHeader );
 202                                 $origins = preg_split( '/\s+/', $originHeader );
 203                         }
 204                         $sessionCookies = array_intersect(
 205                                 array_keys( $_COOKIE ),
 206                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 207                         );
 208                         if ( $origins && $sessionCookies && (
 209                                 count( $origins ) !== 1 || !self::matchOrigin(
 210                                         $origins[0],
 211                                         $config->get( 'CrossSiteAJAXdomains' ),
 212                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 213                                 )
 214                         ) ) {
 215                                 LoggerFactory::getInstance( 'cors' )->warning(
 216                                         'Non-whitelisted CORS request with session cookies', [
 217                                                 'origin' => $originHeader,
 218                                                 'cookies' => $sessionCookies,
 219                                                 'ip' => $request->getIP(),
 220                                                 'userAgent' => $this->getUserAgent(),
 221                                                 'wiki' => wfWikiID(),
 222                                         ]
 223                                 );
 224                         }
 225
 226                         // If we're in a mode that breaks the same-origin policy, strip
 227                         // user credentials for security.
 228                         if ( $this->lacksSameOriginSecurity() ) {
 229                                 global $wgUser;
 230                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 231                                 $wgUser = new User();
 232                                 $this->getContext()->setUser( $wgUser );
 233                                 $request->response()->header( 'MediaWiki-Login-Suppressed: true' );
 234                         }
 235                 }
 236
 237                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 238
 239                 // Setup uselang. This doesn't use $this->getParameter()
 240                 // because we're not ready to handle errors yet.
 241                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 242                 if ( $uselang === 'user' ) {
 243                         // Assume the parent context is going to return the user language
 244                         // for uselang=user (see T85635).
 245                 } else {
 246                         if ( $uselang === 'content' ) {
 247                                 $uselang = MediaWikiServices::getInstance()->getContentLanguage()->getCode();
 248                         }
 249                         $code = RequestContext::sanitizeLangCode( $uselang );
 250                         $this->getContext()->setLanguage( $code );
 251                         if ( !$this->mInternalMode ) {
 252                                 global $wgLang;
 253                                 $wgLang = $this->getContext()->getLanguage();
 254                                 RequestContext::getMain()->setLanguage( $wgLang );
 255                         }
 256                 }
 257
 258                 // Set up the error formatter. This doesn't use $this->getParameter()
 259                 // because we're not ready to handle errors yet.
 260                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 261                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 262                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 263                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 264                         if ( $errorLangCode === 'uselang' ) {
 265                                 $errorLang = $this->getLanguage();
 266                         } elseif ( $errorLangCode === 'content' ) {
 267                                 $errorLang = MediaWikiServices::getInstance()->getContentLanguage();
 268                         } else {
 269                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 270                                 $errorLang = Language::factory( $errorLangCode );
 271                         }
 272                         $this->mErrorFormatter = new ApiErrorFormatter(
 273                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 274                         );
 275                 } else {
 276                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 277                 }
 278                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 279
 280                 $this->mModuleMgr = new ApiModuleManager( $this );
 281                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 282                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 283                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 284                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 285
 286                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 287
 288                 $this->mContinuationManager = null;
 289                 $this->mEnableWrite = $enableWrite;
 290
 291                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 292                 $this->mCommit = false;
 293         }
 294
 295         /**
 296          * Return true if the API was started by other PHP code using FauxRequest
 297          * @return bool
 298          */
 299         public function isInternalMode() {
 300                 return $this->mInternalMode;
 301         }
 302
 303         /**
 304          * Get the ApiResult object associated with current request
 305          *
 306          * @return ApiResult
 307          */
 308         public function getResult() {
 309                 return $this->mResult;
 310         }
 311
 312         /**
 313          * Get the security flag for the current request
 314          * @return bool
 315          */
 316         public function lacksSameOriginSecurity() {
 317                 if ( $this->lacksSameOriginSecurity !== null ) {
 318                         return $this->lacksSameOriginSecurity;
 319                 }
 320
 321                 $request = $this->getRequest();
 322
 323                 // JSONP mode
 324                 if ( $request->getVal( 'callback' ) !== null ) {
 325                         $this->lacksSameOriginSecurity = true;
 326                         return true;
 327                 }
 328
 329                 // Anonymous CORS
 330                 if ( $request->getVal( 'origin' ) === '*' ) {
 331                         $this->lacksSameOriginSecurity = true;
 332                         return true;
 333                 }
 334
 335                 // Header to be used from XMLHTTPRequest when the request might
 336                 // otherwise be used for XSS.
 337                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 338                         $this->lacksSameOriginSecurity = true;
 339                         return true;
 340                 }
 341
 342                 // Allow extensions to override.
 343                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 344                 return $this->lacksSameOriginSecurity;
 345         }
 346
 347         /**
 348          * Get the ApiErrorFormatter object associated with current request
 349          * @return ApiErrorFormatter
 350          */
 351         public function getErrorFormatter() {
 352                 return $this->mErrorFormatter;
 353         }
 354
 355         /**
 356          * Get the continuation manager
 357          * @return ApiContinuationManager|null
 358          */
 359         public function getContinuationManager() {
 360                 return $this->mContinuationManager;
 361         }
 362
 363         /**
 364          * Set the continuation manager
 365          * @param ApiContinuationManager|null $manager
 366          */
 367         public function setContinuationManager( ApiContinuationManager $manager = null ) {
 368                 if ( $manager !== null && $this->mContinuationManager !== null ) {
 369                         throw new UnexpectedValueException(
 370                                 __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 371                                 ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 372                         );
 373                 }
 374                 $this->mContinuationManager = $manager;
 375         }
 376
 377         /**
 378          * Get the API module object. Only works after executeAction()
 379          *
 380          * @return ApiBase
 381          */
 382         public function getModule() {
 383                 return $this->mModule;
 384         }
 385
 386         /**
 387          * Get the result formatter object. Only works after setupExecuteAction()
 388          *
 389          * @return ApiFormatBase
 390          */
 391         public function getPrinter() {
 392                 return $this->mPrinter;
 393         }
 394
 395         /**
 396          * Set how long the response should be cached.
 397          *
 398          * @param int $maxage
 399          */
 400         public function setCacheMaxAge( $maxage ) {
 401                 $this->setCacheControl( [
 402                         'max-age' => $maxage,
 403                         's-maxage' => $maxage
 404                 ] );
 405         }
 406
 407         /**
 408          * Set the type of caching headers which will be sent.
 409          *
 410          * @param string $mode One of:
 411          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 412          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 413          *         not provided by any of these means, the object will be private.
 414          *    - 'private':    Cache this object only in private client-side caches.
 415          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 416          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 417          *         set consistently for a given URL, it cannot be set differently depending on
 418          *         things like the contents of the database, or whether the user is logged in.
 419          *
 420          *  If the wiki does not allow anonymous users to read it, the mode set here
 421          *  will be ignored, and private caching headers will always be sent. In other words,
 422          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 423          *  view.
 424          *
 425          *  For user-dependent data, the private mode should generally be used. The
 426          *  anon-public-user-private mode should only be used where there is a particularly
 427          *  good performance reason for caching the anonymous response, but where the
 428          *  response to logged-in users may differ, or may contain private data.
 429          *
 430          *  If this function is never called, then the default will be the private mode.
 431          */
 432         public function setCacheMode( $mode ) {
 433                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 434                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 435
 436                         // Ignore for forwards-compatibility
 437                         return;
 438                 }
 439
 440                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 441                         // Private wiki, only private headers
 442                         if ( $mode !== 'private' ) {
 443                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 444
 445                                 return;
 446                         }
 447                 }
 448
 449                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 450                         // User language is used for i18n, so we don't want to publicly
 451                         // cache. Anons are ok, because if they have non-default language
 452                         // then there's an appropriate Vary header set by whatever set
 453                         // their non-default language.
 454                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 455                                 "'anon-public-user-private' due to uselang=user\n" );
 456                         $mode = 'anon-public-user-private';
 457                 }
 458
 459                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 460                 $this->mCacheMode = $mode;
 461         }
 462
 463         /**
 464          * Set directives (key/value pairs) for the Cache-Control header.
 465          * Boolean values will be formatted as such, by including or omitting
 466          * without an equals sign.
 467          *
 468          * Cache control values set here will only be used if the cache mode is not
 469          * private, see setCacheMode().
 470          *
 471          * @param array $directives
 472          */
 473         public function setCacheControl( $directives ) {
 474                 $this->mCacheControl = $directives + $this->mCacheControl;
 475         }
 476
 477         /**
 478          * Create an instance of an output formatter by its name
 479          *
 480          * @param string $format
 481          *
 482          * @return ApiFormatBase
 483          */
 484         public function createPrinterByName( $format ) {
 485                 $printer = $this->mModuleMgr->getModule( $format, 'format', /* $ignoreCache */ true );
 486                 if ( $printer === null ) {
 487                         $this->dieWithError(
 488                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 489                         );
 490                 }
 491
 492                 return $printer;
 493         }
 494
 495         /**
 496          * Execute api request. Any errors will be handled if the API was called by the remote client.
 497          */
 498         public function execute() {
 499                 if ( $this->mInternalMode ) {
 500                         $this->executeAction();
 501                 } else {
 502                         $this->executeActionWithErrorHandling();
 503                 }
 504         }
 505
 506         /**
 507          * Execute an action, and in case of an error, erase whatever partial results
 508          * have been accumulated, and replace it with an error message and a help screen.
 509          */
 510         protected function executeActionWithErrorHandling() {
 511                 // Verify the CORS header before executing the action
 512                 if ( !$this->handleCORS() ) {
 513                         // handleCORS() has sent a 403, abort
 514                         return;
 515                 }
 516
 517                 // Exit here if the request method was OPTIONS
 518                 // (assume there will be a followup GET or POST)
 519                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 520                         return;
 521                 }
 522
 523                 // In case an error occurs during data output,
 524                 // clear the output buffer and print just the error information
 525                 $obLevel = ob_get_level();
 526                 ob_start();
 527
 528                 $t = microtime( true );
 529                 $isError = false;
 530                 try {
 531                         $this->executeAction();
 532                         $runTime = microtime( true ) - $t;
 533                         $this->logRequest( $runTime );
 534                         MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 535                                 'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 536                         );
 537                 } catch ( Exception $e ) { // @todo Remove this block when HHVM is no longer supported
 538                         $this->handleException( $e );
 539                         $this->logRequest( microtime( true ) - $t, $e );
 540                         $isError = true;
 541                 } catch ( Throwable $e ) {
 542                         $this->handleException( $e );
 543                         $this->logRequest( microtime( true ) - $t, $e );
 544                         $isError = true;
 545                 }
 546
 547                 // Commit DBs and send any related cookies and headers
 548                 MediaWiki::preOutputCommit( $this->getContext() );
 549
 550                 // Send cache headers after any code which might generate an error, to
 551                 // avoid sending public cache headers for errors.
 552                 $this->sendCacheHeaders( $isError );
 553
 554                 // Executing the action might have already messed with the output
 555                 // buffers.
 556                 while ( ob_get_level() > $obLevel ) {
 557                         ob_end_flush();
 558                 }
 559         }
 560
 561         /**
 562          * Handle an exception as an API response
 563          *
 564          * @since 1.23
 565          * @param Exception|Throwable $e
 566          */
 567         protected function handleException( $e ) {
 568                 // T65145: Rollback any open database transactions
 569                 if ( !$e instanceof ApiUsageException ) {
 570                         // ApiUsageExceptions are intentional, so don't rollback if that's the case
 571                         MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 572                 }
 573
 574                 // Allow extra cleanup and logging
 575                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 576
 577                 // Handle any kind of exception by outputting properly formatted error message.
 578                 // If this fails, an unhandled exception should be thrown so that global error
 579                 // handler will process and log it.
 580
 581                 $errCodes = $this->substituteResultWithError( $e );
 582
 583                 // Error results should not be cached
 584                 $this->setCacheMode( 'private' );
 585
 586                 $response = $this->getRequest()->response();
 587                 $headerStr = 'MediaWiki-API-Error: ' . implode( ', ', $errCodes );
 588                 $response->header( $headerStr );
 589
 590                 // Reset and print just the error message
 591                 ob_clean();
 592
 593                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 594                 $this->createErrorPrinter();
 595
 596                 $failed = false;
 597                 try {
 598                         $this->printResult( $e->getCode() );
 599                 } catch ( ApiUsageException $ex ) {
 600                         // The error printer itself is failing. Try suppressing its request
 601                         // parameters and redo.
 602                         $failed = true;
 603                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 604                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 605                                 try {
 606                                         $this->mPrinter->addWarning( $error );
 607                                 } catch ( Exception $ex2 ) { // @todo Remove this block when HHVM is no longer supported
 608                                         // WTF?
 609                                         $this->addWarning( $error );
 610                                 } catch ( Throwable $ex2 ) {
 611                                         // WTF?
 612                                         $this->addWarning( $error );
 613                                 }
 614                         }
 615                 }
 616                 if ( $failed ) {
 617                         $this->mPrinter = null;
 618                         $this->createErrorPrinter();
 619                         $this->mPrinter->forceDefaultParams();
 620                         if ( $e->getCode() ) {
 621                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 622                         }
 623                         $this->printResult( $e->getCode() );
 624                 }
 625         }
 626
 627         /**
 628          * Handle an exception from the ApiBeforeMain hook.
 629          *
 630          * This tries to print the exception as an API response, to be more
 631          * friendly to clients. If it fails, it will rethrow the exception.
 632          *
 633          * @since 1.23
 634          * @param Exception|Throwable $e
 635          * @throws Exception|Throwable
 636          */
 637         public static function handleApiBeforeMainException( $e ) {
 638                 ob_start();
 639
 640                 try {
 641                         $main = new self( RequestContext::getMain(), false );
 642                         $main->handleException( $e );
 643                         $main->logRequest( 0, $e );
 644                 } catch ( Exception $e2 ) { // @todo Remove this block when HHVM is no longer supported
 645                         // Nope, even that didn't work. Punt.
 646                         throw $e;
 647                 } catch ( Throwable $e2 ) {
 648                         // Nope, even that didn't work. Punt.
 649                         throw $e;
 650                 }
 651
 652                 // Reset cache headers
 653                 $main->sendCacheHeaders( true );
 654
 655                 ob_end_flush();
 656         }
 657
 658         /**
 659          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 660          *
 661          * If no origin parameter is present, nothing happens.
 662          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 663          * is set and false is returned.
 664          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 665          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 666          * headers are set.
 667          * https://www.w3.org/TR/cors/#resource-requests
 668          * https://www.w3.org/TR/cors/#resource-preflight-requests
 669          *
 670          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 671          */
 672         protected function handleCORS() {
 673                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 674                 if ( $originParam === null ) {
 675                         // No origin parameter, nothing to do
 676                         return true;
 677                 }
 678
 679                 $request = $this->getRequest();
 680                 $response = $request->response();
 681
 682                 $matchedOrigin = false;
 683                 $allowTiming = false;
 684                 $varyOrigin = true;
 685
 686                 if ( $originParam === '*' ) {
 687                         // Request for anonymous CORS
 688                         // Technically we should check for the presence of an Origin header
 689                         // and not process it as CORS if it's not set, but that would
 690                         // require us to vary on Origin for all 'origin=*' requests which
 691                         // we don't want to do.
 692                         $matchedOrigin = true;
 693                         $allowOrigin = '*';
 694                         $allowCredentials = 'false';
 695                         $varyOrigin = false; // No need to vary
 696                 } else {
 697                         // Non-anonymous CORS, check we allow the domain
 698
 699                         // Origin: header is a space-separated list of origins, check all of them
 700                         $originHeader = $request->getHeader( 'Origin' );
 701                         if ( $originHeader === false ) {
 702                                 $origins = [];
 703                         } else {
 704                                 $originHeader = trim( $originHeader );
 705                                 $origins = preg_split( '/\s+/', $originHeader );
 706                         }
 707
 708                         if ( !in_array( $originParam, $origins ) ) {
 709                                 // origin parameter set but incorrect
 710                                 // Send a 403 response
 711                                 $response->statusHeader( 403 );
 712                                 $response->header( 'Cache-Control: no-cache' );
 713                                 echo "'origin' parameter does not match Origin header\n";
 714
 715                                 return false;
 716                         }
 717
 718                         $config = $this->getConfig();
 719                         $matchedOrigin = count( $origins ) === 1 && self::matchOrigin(
 720                                 $originParam,
 721                                 $config->get( 'CrossSiteAJAXdomains' ),
 722                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 723                         );
 724
 725                         $allowOrigin = $originHeader;
 726                         $allowCredentials = 'true';
 727                         $allowTiming = $originHeader;
 728                 }
 729
 730                 if ( $matchedOrigin ) {
 731                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 732                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 733                         if ( $preflight ) {
 734                                 // This is a CORS preflight request
 735                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 736                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 737                                         $response->header( 'MediaWiki-CORS-Rejection: Unsupported method requested in preflight' );
 738                                         return true;
 739                                 }
 740                                 // We allow the actual request to send the following headers
 741                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 742                                 if ( $requestedHeaders !== false ) {
 743                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 744                                                 $response->header( 'MediaWiki-CORS-Rejection: Unsupported header requested in preflight' );
 745                                                 return true;
 746                                         }
 747                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 748                                 }
 749
 750                                 // We only allow the actual request to be GET or POST
 751                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 752                         } elseif ( $request->getMethod() !== 'POST' && $request->getMethod() !== 'GET' ) {
 753                                 // Unsupported non-preflight method, don't handle it as CORS
 754                                 $response->header(
 755                                         'MediaWiki-CORS-Rejection: Unsupported method for simple request or actual request'
 756                                 );
 757                                 return true;
 758                         }
 759
 760                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 761                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 762                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 763                         if ( $allowTiming !== false ) {
 764                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 765                         }
 766
 767                         if ( !$preflight ) {
 768                                 $response->header(
 769                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag, '
 770                                         . 'MediaWiki-Login-Suppressed'
 771                                 );
 772                         }
 773                 } else {
 774                         $response->header( 'MediaWiki-CORS-Rejection: Origin mismatch' );
 775                 }
 776
 777                 if ( $varyOrigin ) {
 778                         $this->getOutput()->addVaryHeader( 'Origin' );
 779                 }
 780
 781                 return true;
 782         }
 783
 784         /**
 785          * Attempt to match an Origin header against a set of rules and a set of exceptions
 786          * @param string $value Origin header
 787          * @param array $rules Set of wildcard rules
 788          * @param array $exceptions Set of wildcard rules
 789          * @return bool True if $value matches a rule in $rules and doesn't match
 790          *    any rules in $exceptions, false otherwise
 791          */
 792         protected static function matchOrigin( $value, $rules, $exceptions ) {
 793                 foreach ( $rules as $rule ) {
 794                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 795                                 // Rule matches, check exceptions
 796                                 foreach ( $exceptions as $exc ) {
 797                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 798                                                 return false;
 799                                         }
 800                                 }
 801
 802                                 return true;
 803                         }
 804                 }
 805
 806                 return false;
 807         }
 808
 809         /**
 810          * Attempt to validate the value of Access-Control-Request-Headers against a list
 811          * of headers that we allow the follow up request to send.
 812          *
 813          * @param string $requestedHeaders Comma separated list of HTTP headers
 814          * @return bool True if all requested headers are in the list of allowed headers
 815          */
 816         protected static function matchRequestedHeaders( $requestedHeaders ) {
 817                 if ( trim( $requestedHeaders ) === '' ) {
 818                         return true;
 819                 }
 820                 $requestedHeaders = explode( ',', $requestedHeaders );
 821                 $allowedAuthorHeaders = array_flip( [
 822                         /* simple headers (see spec) */
 823                         'accept',
 824                         'accept-language',
 825                         'content-language',
 826                         'content-type',
 827                         /* non-authorable headers in XHR, which are however requested by some UAs */
 828                         'accept-encoding',
 829                         'dnt',
 830                         'origin',
 831                         /* MediaWiki whitelist */
 832                         'api-user-agent',
 833                 ] );
 834                 foreach ( $requestedHeaders as $rHeader ) {
 835                         $rHeader = strtolower( trim( $rHeader ) );
 836                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 837                                 LoggerFactory::getInstance( 'api-warning' )->warning(
 838                                         'CORS preflight failed on requested header: {header}', [
 839                                                 'header' => $rHeader
 840                                         ]
 841                                 );
 842                                 return false;
 843                         }
 844                 }
 845                 return true;
 846         }
 847
 848         /**
 849          * Helper function to convert wildcard string into a regex
 850          * '*' => '.*?'
 851          * '?' => '.'
 852          *
 853          * @param string $wildcard String with wildcards
 854          * @return string Regular expression
 855          */
 856         protected static function wildcardToRegex( $wildcard ) {
 857                 $wildcard = preg_quote( $wildcard, '/' );
 858                 $wildcard = str_replace(
 859                         [ '\*', '\?' ],
 860                         [ '.*?', '.' ],
 861                         $wildcard
 862                 );
 863
 864                 return "/^https?:\/\/$wildcard$/";
 865         }
 866
 867         /**
 868          * Send caching headers
 869          * @param bool $isError Whether an error response is being output
 870          * @since 1.26 added $isError parameter
 871          */
 872         protected function sendCacheHeaders( $isError ) {
 873                 $response = $this->getRequest()->response();
 874                 $out = $this->getOutput();
 875
 876                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 877
 878                 $config = $this->getConfig();
 879
 880                 if ( $config->get( 'VaryOnXFP' ) ) {
 881                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 882                 }
 883
 884                 if ( !$isError && $this->mModule &&
 885                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 886                 ) {
 887                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 888                         if ( $etag !== null ) {
 889                                 $response->header( "ETag: $etag" );
 890                         }
 891                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 892                         if ( $lastMod !== null ) {
 893                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 894                         }
 895                 }
 896
 897                 // The logic should be:
 898                 // $this->mCacheControl['max-age'] is set?
 899                 //    Use it, the module knows better than our guess.
 900                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 901                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 902                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 903                 $maxage = 0;
 904                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 905                         $maxage = $this->mCacheControl['max-age'];
 906                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 907                         $this->mCacheMode !== 'private'
 908                 ) {
 909                         $maxage = $this->getParameter( 'maxage' );
 910                 }
 911                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 912
 913                 if ( $this->mCacheMode == 'private' ) {
 914                         $response->header( "Cache-Control: $privateCache" );
 915                         return;
 916                 }
 917
 918                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 919                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 920                         $out->addVaryHeader( 'Cookie' );
 921                         $response->header( $out->getVaryHeader() );
 922                         if ( $useKeyHeader ) {
 923                                 $response->header( $out->getKeyHeader() );
 924                                 if ( $out->haveCacheVaryCookies() ) {
 925                                         // Logged in, mark this request private
 926                                         $response->header( "Cache-Control: $privateCache" );
 927                                         return;
 928                                 }
 929                                 // Logged out, send normal public headers below
 930                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 931                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 932                                 // Mark request private
 933                                 $response->header( "Cache-Control: $privateCache" );
 934
 935                                 return;
 936                         } // else no Key and anonymous, send public headers below
 937                 }
 938
 939                 // Send public headers
 940                 $response->header( $out->getVaryHeader() );
 941                 if ( $useKeyHeader ) {
 942                         $response->header( $out->getKeyHeader() );
 943                 }
 944
 945                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 946                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 947                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 948                 }
 949                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 950                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 951                 }
 952
 953                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 954                         // Public cache not requested
 955                         // Sending a Vary header in this case is harmless, and protects us
 956                         // against conditional calls of setCacheMaxAge().
 957                         $response->header( "Cache-Control: $privateCache" );
 958
 959                         return;
 960                 }
 961
 962                 $this->mCacheControl['public'] = true;
 963
 964                 // Send an Expires header
 965                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 966                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 967                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 968
 969                 // Construct the Cache-Control header
 970                 $ccHeader = '';
 971                 $separator = '';
 972                 foreach ( $this->mCacheControl as $name => $value ) {
 973                         if ( is_bool( $value ) ) {
 974                                 if ( $value ) {
 975                                         $ccHeader .= $separator . $name;
 976                                         $separator = ', ';
 977                                 }
 978                         } else {
 979                                 $ccHeader .= $separator . "$name=$value";
 980                                 $separator = ', ';
 981                         }
 982                 }
 983
 984                 $response->header( "Cache-Control: $ccHeader" );
 985         }
 986
 987         /**
 988          * Create the printer for error output
 989          */
 990         private function createErrorPrinter() {
 991                 if ( !isset( $this->mPrinter ) ) {
 992                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 993                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 994                                 $value = self::API_DEFAULT_FORMAT;
 995                         }
 996                         $this->mPrinter = $this->createPrinterByName( $value );
 997                 }
 998
 999                 // Printer may not be able to handle errors. This is particularly
1000                 // likely if the module returns something for getCustomPrinter().
1001                 if ( !$this->mPrinter->canPrintErrors() ) {
1002                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1003                 }
1004         }
1005
1006         /**
1007          * Create an error message for the given exception.
1008          *
1009          * If an ApiUsageException, errors/warnings will be extracted from the
1010          * embedded StatusValue.
1011          *
1012          * Any other exception will be returned with a generic code and wrapper
1013          * text around the exception's (presumably English) message as a single
1014          * error (no warnings).
1015          *
1016          * @param Exception|Throwable $e
1017          * @param string $type 'error' or 'warning'
1018          * @return ApiMessage[]
1019          * @since 1.27
1020          */
1021         protected function errorMessagesFromException( $e, $type = 'error' ) {
1022                 $messages = [];
1023                 if ( $e instanceof ApiUsageException ) {
1024                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1025                                 $messages[] = ApiMessage::create( $error );
1026                         }
1027                 } elseif ( $type !== 'error' ) {
1028                         // None of the rest have any messages for non-error types
1029                 } else {
1030                         // Something is seriously wrong
1031                         $config = $this->getConfig();
1032                         // TODO: Avoid embedding arbitrary class names in the error code.
1033                         $class = preg_replace( '#^Wikimedia\\\Rdbms\\\#', '', get_class( $e ) );
1034                         $code = 'internal_api_error_' . $class;
1035                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1036                                 if ( $e instanceof ILocalizedException ) {
1037                                         $msg = $e->getMessageObject();
1038                                 } elseif ( $e instanceof MessageSpecifier ) {
1039                                         $msg = Message::newFromSpecifier( $e );
1040                                 } else {
1041                                         $msg = wfEscapeWikiText( $e->getMessage() );
1042                                 }
1043                                 $params = [ 'apierror-exceptioncaught', WebRequest::getRequestId(), $msg ];
1044                         } else {
1045                                 $params = [ 'apierror-exceptioncaughttype', WebRequest::getRequestId(), get_class( $e ) ];
1046                         }
1047
1048                         $messages[] = ApiMessage::create( $params, $code );
1049                 }
1050                 return $messages;
1051         }
1052
1053         /**
1054          * Replace the result data with the information about an exception.
1055          * @param Exception|Throwable $e
1056          * @return string[] Error codes
1057          */
1058         protected function substituteResultWithError( $e ) {
1059                 $result = $this->getResult();
1060                 $formatter = $this->getErrorFormatter();
1061                 $config = $this->getConfig();
1062                 $errorCodes = [];
1063
1064                 // Remember existing warnings and errors across the reset
1065                 $errors = $result->getResultData( [ 'errors' ] );
1066                 $warnings = $result->getResultData( [ 'warnings' ] );
1067                 $result->reset();
1068                 if ( $warnings !== null ) {
1069                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1070                 }
1071                 if ( $errors !== null ) {
1072                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1073
1074                         // Collect the copied error codes for the return value
1075                         foreach ( $errors as $error ) {
1076                                 if ( isset( $error['code'] ) ) {
1077                                         $errorCodes[$error['code']] = true;
1078                                 }
1079                         }
1080                 }
1081
1082                 // Add errors from the exception
1083                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1084                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1085                         if ( ApiErrorFormatter::isValidApiCode( $msg->getApiCode() ) ) {
1086                                 $errorCodes[$msg->getApiCode()] = true;
1087                         } else {
1088                                 LoggerFactory::getInstance( 'api-warning' )->error( 'Invalid API error code "{code}"', [
1089                                         'code' => $msg->getApiCode(),
1090                                         'exception' => $e,
1091                                 ] );
1092                                 $errorCodes['<invalid-code>'] = true;
1093                         }
1094                         $formatter->addError( $modulePath, $msg );
1095                 }
1096                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1097                         $formatter->addWarning( $modulePath, $msg );
1098                 }
1099
1100                 // Add additional data. Path depends on whether we're in BC mode or not.
1101                 // Data depends on the type of exception.
1102                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1103                         $path = [ 'error' ];
1104                 } else {
1105                         $path = null;
1106                 }
1107                 if ( $e instanceof ApiUsageException ) {
1108                         $link = wfExpandUrl( wfScript( 'api' ) );
1109                         $result->addContentValue(
1110                                 $path,
1111                                 'docref',
1112                                 trim(
1113                                         $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1114                                         . ' '
1115                                         . $this->msg( 'api-usage-mailinglist-ref' )->inLanguage( $formatter->getLanguage() )->text()
1116                                 )
1117                         );
1118                 } else {
1119                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1120                                 $result->addContentValue(
1121                                         $path,
1122                                         'trace',
1123                                         $this->msg( 'api-exception-trace',
1124                                                 get_class( $e ),
1125                                                 $e->getFile(),
1126                                                 $e->getLine(),
1127                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1128                                         )->inLanguage( $formatter->getLanguage() )->text()
1129                                 );
1130                         }
1131                 }
1132
1133                 // Add the id and such
1134                 $this->addRequestedFields( [ 'servedby' ] );
1135
1136                 return array_keys( $errorCodes );
1137         }
1138
1139         /**
1140          * Add requested fields to the result
1141          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1142          *  - servedby
1143          */
1144         protected function addRequestedFields( $force = [] ) {
1145                 $result = $this->getResult();
1146
1147                 $requestid = $this->getParameter( 'requestid' );
1148                 if ( $requestid !== null ) {
1149                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1150                 }
1151
1152                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1153                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1154                 ) ) {
1155                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1156                 }
1157
1158                 if ( $this->getParameter( 'curtimestamp' ) ) {
1159                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1160                                 ApiResult::NO_SIZE_CHECK );
1161                 }
1162
1163                 if ( $this->getParameter( 'responselanginfo' ) ) {
1164                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1165                                 ApiResult::NO_SIZE_CHECK );
1166                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1167                                 ApiResult::NO_SIZE_CHECK );
1168                 }
1169         }
1170
1171         /**
1172          * Set up for the execution.
1173          * @return array
1174          */
1175         protected function setupExecuteAction() {
1176                 $this->addRequestedFields();
1177
1178                 $params = $this->extractRequestParams();
1179                 $this->mAction = $params['action'];
1180
1181                 return $params;
1182         }
1183
1184         /**
1185          * Set up the module for response
1186          * @return ApiBase The module that will handle this action
1187          * @throws MWException
1188          * @throws ApiUsageException
1189          */
1190         protected function setupModule() {
1191                 // Instantiate the module requested by the user
1192                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1193                 if ( $module === null ) {
1194                         // Probably can't happen
1195                         // @codeCoverageIgnoreStart
1196                         $this->dieWithError(
1197                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1198                         );
1199                         // @codeCoverageIgnoreEnd
1200                 }
1201                 $moduleParams = $module->extractRequestParams();
1202
1203                 // Check token, if necessary
1204                 if ( $module->needsToken() === true ) {
1205                         throw new MWException(
1206                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1207                                 'See documentation for ApiBase::needsToken for details.'
1208                         );
1209                 }
1210                 if ( $module->needsToken() ) {
1211                         if ( !$module->mustBePosted() ) {
1212                                 throw new MWException(
1213                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1214                                 );
1215                         }
1216
1217                         if ( !isset( $moduleParams['token'] ) ) {
1218                                 // Probably can't happen
1219                                 // @codeCoverageIgnoreStart
1220                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1221                                 // @codeCoverageIgnoreEnd
1222                         }
1223
1224                         $module->requirePostedParameters( [ 'token' ] );
1225
1226                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1227                                 $module->dieWithError( 'apierror-badtoken' );
1228                         }
1229                 }
1230
1231                 return $module;
1232         }
1233
1234         /**
1235          * @return array
1236          */
1237         private function getMaxLag() {
1238                 $dbLag = MediaWikiServices::getInstance()->getDBLoadBalancer()->getMaxLag();
1239                 $lagInfo = [
1240                         'host' => $dbLag[0],
1241                         'lag' => $dbLag[1],
1242                         'type' => 'db'
1243                 ];
1244
1245                 $jobQueueLagFactor = $this->getConfig()->get( 'JobQueueIncludeInMaxLagFactor' );
1246                 if ( $jobQueueLagFactor ) {
1247                         // Turn total number of jobs into seconds by using the configured value
1248                         $totalJobs = array_sum( JobQueueGroup::singleton()->getQueueSizes() );
1249                         $jobQueueLag = $totalJobs / (float)$jobQueueLagFactor;
1250                         if ( $jobQueueLag > $lagInfo['lag'] ) {
1251                                 $lagInfo = [
1252                                         'host' => wfHostname(), // XXX: Is there a better value that could be used?
1253                                         'lag' => $jobQueueLag,
1254                                         'type' => 'jobqueue',
1255                                         'jobs' => $totalJobs,
1256                                 ];
1257                         }
1258                 }
1259
1260                 Hooks::runWithoutAbort( 'ApiMaxLagInfo', [ &$lagInfo ] );
1261
1262                 return $lagInfo;
1263         }
1264
1265         /**
1266          * Check the max lag if necessary
1267          * @param ApiBase $module Api module being used
1268          * @param array $params Array an array containing the request parameters.
1269          * @return bool True on success, false should exit immediately
1270          */
1271         protected function checkMaxLag( $module, $params ) {
1272                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1273                         $maxLag = $params['maxlag'];
1274                         $lagInfo = $this->getMaxLag();
1275                         if ( $lagInfo['lag'] > $maxLag ) {
1276                                 $response = $this->getRequest()->response();
1277
1278                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1279                                 $response->header( 'X-Database-Lag: ' . intval( $lagInfo['lag'] ) );
1280
1281                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1282                                         $this->dieWithError(
1283                                                 [ 'apierror-maxlag', $lagInfo['lag'], $lagInfo['host'] ],
1284                                                 'maxlag',
1285                                                 $lagInfo
1286                                         );
1287                                 }
1288
1289                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lagInfo['lag'] ], 'maxlag', $lagInfo );
1290                         }
1291                 }
1292
1293                 return true;
1294         }
1295
1296         /**
1297          * Check selected RFC 7232 precondition headers
1298          *
1299          * RFC 7232 envisions a particular model where you send your request to "a
1300          * resource", and for write requests that you can read "the resource" by
1301          * changing the method to GET. When the API receives a GET request, it
1302          * works out even though "the resource" from RFC 7232's perspective might
1303          * be many resources from MediaWiki's perspective. But it totally fails for
1304          * a POST, since what HTTP sees as "the resource" is probably just
1305          * "/api.php" with all the interesting bits in the body.
1306          *
1307          * Therefore, we only support RFC 7232 precondition headers for GET (and
1308          * HEAD). That means we don't need to bother with If-Match and
1309          * If-Unmodified-Since since they only apply to modification requests.
1310          *
1311          * And since we don't support Range, If-Range is ignored too.
1312          *
1313          * @since 1.26
1314          * @param ApiBase $module Api module being used
1315          * @return bool True on success, false should exit immediately
1316          */
1317         protected function checkConditionalRequestHeaders( $module ) {
1318                 if ( $this->mInternalMode ) {
1319                         // No headers to check in internal mode
1320                         return true;
1321                 }
1322
1323                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1324                         // Don't check POSTs
1325                         return true;
1326                 }
1327
1328                 $return304 = false;
1329
1330                 $ifNoneMatch = array_diff(
1331                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1332                         [ '' ]
1333                 );
1334                 if ( $ifNoneMatch ) {
1335                         if ( $ifNoneMatch === [ '*' ] ) {
1336                                 // API responses always "exist"
1337                                 $etag = '*';
1338                         } else {
1339                                 $etag = $module->getConditionalRequestData( 'etag' );
1340                         }
1341                 }
1342                 if ( $ifNoneMatch && $etag !== null ) {
1343                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1344                         $match = array_map( function ( $s ) {
1345                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1346                         }, $ifNoneMatch );
1347                         $return304 = in_array( $test, $match, true );
1348                 } else {
1349                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1350
1351                         // Some old browsers sends sizes after the date, like this:
1352                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1353                         // Ignore that.
1354                         $i = strpos( $value, ';' );
1355                         if ( $i !== false ) {
1356                                 $value = trim( substr( $value, 0, $i ) );
1357                         }
1358
1359                         if ( $value !== '' ) {
1360                                 try {
1361                                         $ts = new MWTimestamp( $value );
1362                                         if (
1363                                                 // RFC 7231 IMF-fixdate
1364                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1365                                                 // RFC 850
1366                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1367                                                 // asctime (with and without space-padded day)
1368                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1369                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1370                                         ) {
1371                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1372                                                 if ( $lastMod !== null ) {
1373                                                         // Mix in some MediaWiki modification times
1374                                                         $modifiedTimes = [
1375                                                                 'page' => $lastMod,
1376                                                                 'user' => $this->getUser()->getTouched(),
1377                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1378                                                         ];
1379                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1380                                                                 // T46570: the core page itself may not change, but resources might
1381                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1382                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1383                                                                 );
1384                                                         }
1385                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1386                                                         $lastMod = max( $modifiedTimes );
1387                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1388                                                 }
1389                                         }
1390                                 } catch ( TimestampException $e ) {
1391                                         // Invalid timestamp, ignore it
1392                                 }
1393                         }
1394                 }
1395
1396                 if ( $return304 ) {
1397                         $this->getRequest()->response()->statusHeader( 304 );
1398
1399                         // Avoid outputting the compressed representation of a zero-length body
1400                         Wikimedia\suppressWarnings();
1401                         ini_set( 'zlib.output_compression', 0 );
1402                         Wikimedia\restoreWarnings();
1403                         wfClearOutputBuffers();
1404
1405                         return false;
1406                 }
1407
1408                 return true;
1409         }
1410
1411         /**
1412          * Check for sufficient permissions to execute
1413          * @param ApiBase $module An Api module
1414          */
1415         protected function checkExecutePermissions( $module ) {
1416                 $user = $this->getUser();
1417                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1418                         !$user->isAllowed( 'read' )
1419                 ) {
1420                         $this->dieWithError( 'apierror-readapidenied' );
1421                 }
1422
1423                 if ( $module->isWriteMode() ) {
1424                         if ( !$this->mEnableWrite ) {
1425                                 $this->dieWithError( 'apierror-noapiwrite' );
1426                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1427                                 $this->dieWithError( 'apierror-writeapidenied' );
1428                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1429                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1430                         }
1431
1432                         $this->checkReadOnly( $module );
1433                 }
1434
1435                 // Allow extensions to stop execution for arbitrary reasons.
1436                 $message = 'hookaborted';
1437                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1438                         $this->dieWithError( $message );
1439                 }
1440         }
1441
1442         /**
1443          * Check if the DB is read-only for this user
1444          * @param ApiBase $module An Api module
1445          */
1446         protected function checkReadOnly( $module ) {
1447                 if ( wfReadOnly() ) {
1448                         $this->dieReadOnly();
1449                 }
1450
1451                 if ( $module->isWriteMode()
1452                         && $this->getUser()->isBot()
1453                         && MediaWikiServices::getInstance()->getDBLoadBalancer()->getServerCount() > 1
1454                 ) {
1455                         $this->checkBotReadOnly();
1456                 }
1457         }
1458
1459         /**
1460          * Check whether we are readonly for bots
1461          */
1462         private function checkBotReadOnly() {
1463                 // Figure out how many servers have passed the lag threshold
1464                 $numLagged = 0;
1465                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1466                 $laggedServers = [];
1467                 $loadBalancer = MediaWikiServices::getInstance()->getDBLoadBalancer();
1468                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1469                         if ( $lag > $lagLimit ) {
1470                                 ++$numLagged;
1471                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1472                         }
1473                 }
1474
1475                 // If a majority of replica DBs are too lagged then disallow writes
1476                 $replicaCount = $loadBalancer->getServerCount() - 1;
1477                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1478                         $laggedServers = implode( ', ', $laggedServers );
1479                         wfDebugLog(
1480                                 'api-readonly', // Deprecate this channel in favor of api-warning?
1481                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1482                         );
1483                         LoggerFactory::getInstance( 'api-warning' )->warning(
1484                                 "Api request failed as read only because the following DBs are lagged: {laggeddbs}", [
1485                                         'laggeddbs' => $laggedServers,
1486                                 ]
1487                         );
1488
1489                         $this->dieWithError(
1490                                 'readonly_lag',
1491                                 'readonly',
1492                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1493                         );
1494                 }
1495         }
1496
1497         /**
1498          * Check asserts of the user's rights
1499          * @param array $params
1500          */
1501         protected function checkAsserts( $params ) {
1502                 if ( isset( $params['assert'] ) ) {
1503                         $user = $this->getUser();
1504                         switch ( $params['assert'] ) {
1505                                 case 'user':
1506                                         if ( $user->isAnon() ) {
1507                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1508                                         }
1509                                         break;
1510                                 case 'bot':
1511                                         if ( !$user->isAllowed( 'bot' ) ) {
1512                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1513                                         }
1514                                         break;
1515                         }
1516                 }
1517                 if ( isset( $params['assertuser'] ) ) {
1518                         $assertUser = User::newFromName( $params['assertuser'], false );
1519                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1520                                 $this->dieWithError(
1521                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1522                                 );
1523                         }
1524                 }
1525         }
1526
1527         /**
1528          * Check POST for external response and setup result printer
1529          * @param ApiBase $module An Api module
1530          * @param array $params An array with the request parameters
1531          */
1532         protected function setupExternalResponse( $module, $params ) {
1533                 $validMethods = [ 'GET', 'HEAD', 'POST', 'OPTIONS' ];
1534                 $request = $this->getRequest();
1535
1536                 if ( !in_array( $request->getMethod(), $validMethods ) ) {
1537                         $this->dieWithError( 'apierror-invalidmethod', null, null, 405 );
1538                 }
1539
1540                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1541                         // Module requires POST. GET request might still be allowed
1542                         // if $wgDebugApi is true, otherwise fail.
1543                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1544                 }
1545
1546                 // See if custom printer is used
1547                 $this->mPrinter = $module->getCustomPrinter();
1548                 if ( is_null( $this->mPrinter ) ) {
1549                         // Create an appropriate printer
1550                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1551                 }
1552
1553                 if ( $request->getProtocol() === 'http' && (
1554                         $request->getSession()->shouldForceHTTPS() ||
1555                         ( $this->getUser()->isLoggedIn() &&
1556                                 $this->getUser()->requiresHTTPS() )
1557                 ) ) {
1558                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1559                 }
1560         }
1561
1562         /**
1563          * Execute the actual module, without any error handling
1564          */
1565         protected function executeAction() {
1566                 $params = $this->setupExecuteAction();
1567
1568                 // Check asserts early so e.g. errors in parsing a module's parameters due to being
1569                 // logged out don't override the client's intended "am I logged in?" check.
1570                 $this->checkAsserts( $params );
1571
1572                 $module = $this->setupModule();
1573                 $this->mModule = $module;
1574
1575                 if ( !$this->mInternalMode ) {
1576                         $this->setRequestExpectations( $module );
1577                 }
1578
1579                 $this->checkExecutePermissions( $module );
1580
1581                 if ( !$this->checkMaxLag( $module, $params ) ) {
1582                         return;
1583                 }
1584
1585                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1586                         return;
1587                 }
1588
1589                 if ( !$this->mInternalMode ) {
1590                         $this->setupExternalResponse( $module, $params );
1591                 }
1592
1593                 // Execute
1594                 $module->execute();
1595                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1596
1597                 $this->reportUnusedParams();
1598
1599                 if ( !$this->mInternalMode ) {
1600                         // append Debug information
1601                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1602
1603                         // Print result data
1604                         $this->printResult();
1605                 }
1606         }
1607
1608         /**
1609          * Set database connection, query, and write expectations given this module request
1610          * @param ApiBase $module
1611          */
1612         protected function setRequestExpectations( ApiBase $module ) {
1613                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1614                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1615                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1616                 if ( $this->getRequest()->hasSafeMethod() ) {
1617                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1618                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1619                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1620                         $this->getRequest()->markAsSafeRequest();
1621                 } else {
1622                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1623                 }
1624         }
1625
1626         /**
1627          * Log the preceding request
1628          * @param float $time Time in seconds
1629          * @param Exception|Throwable|null $e Exception caught while processing the request
1630          */
1631         protected function logRequest( $time, $e = null ) {
1632                 $request = $this->getRequest();
1633                 $logCtx = [
1634                         'ts' => time(),
1635                         'ip' => $request->getIP(),
1636                         'userAgent' => $this->getUserAgent(),
1637                         'wiki' => wfWikiID(),
1638                         'timeSpentBackend' => (int)round( $time * 1000 ),
1639                         'hadError' => $e !== null,
1640                         'errorCodes' => [],
1641                         'params' => [],
1642                 ];
1643
1644                 if ( $e ) {
1645                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1646                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1647                         }
1648                 }
1649
1650                 // Construct space separated message for 'api' log channel
1651                 $msg = "API {$request->getMethod()} " .
1652                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1653                         " {$logCtx['ip']} " .
1654                         "T={$logCtx['timeSpentBackend']}ms";
1655
1656                 $sensitive = array_flip( $this->getSensitiveParams() );
1657                 foreach ( $this->getParamsUsed() as $name ) {
1658                         $value = $request->getVal( $name );
1659                         if ( $value === null ) {
1660                                 continue;
1661                         }
1662
1663                         if ( isset( $sensitive[$name] ) ) {
1664                                 $value = '[redacted]';
1665                                 $encValue = '[redacted]';
1666                         } elseif ( strlen( $value ) > 256 ) {
1667                                 $value = substr( $value, 0, 256 );
1668                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1669                         } else {
1670                                 $encValue = $this->encodeRequestLogValue( $value );
1671                         }
1672
1673                         $logCtx['params'][$name] = $value;
1674                         $msg .= " {$name}={$encValue}";
1675                 }
1676
1677                 wfDebugLog( 'api', $msg, 'private' );
1678                 // ApiAction channel is for structured data consumers
1679                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1680         }
1681
1682         /**
1683          * Encode a value in a format suitable for a space-separated log line.
1684          * @param string $s
1685          * @return string
1686          */
1687         protected function encodeRequestLogValue( $s ) {
1688                 static $table;
1689                 if ( !$table ) {
1690                         $chars = ';@$!*(),/:';
1691                         $numChars = strlen( $chars );
1692                         for ( $i = 0; $i < $numChars; $i++ ) {
1693                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1694                         }
1695                 }
1696
1697                 return strtr( rawurlencode( $s ), $table );
1698         }
1699
1700         /**
1701          * Get the request parameters used in the course of the preceding execute() request
1702          * @return array
1703          */
1704         protected function getParamsUsed() {
1705                 return array_keys( $this->mParamsUsed );
1706         }
1707
1708         /**
1709          * Mark parameters as used
1710          * @param string|string[] $params
1711          */
1712         public function markParamsUsed( $params ) {
1713                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1714         }
1715
1716         /**
1717          * Get the request parameters that should be considered sensitive
1718          * @since 1.29
1719          * @return array
1720          */
1721         protected function getSensitiveParams() {
1722                 return array_keys( $this->mParamsSensitive );
1723         }
1724
1725         /**
1726          * Mark parameters as sensitive
1727          * @since 1.29
1728          * @param string|string[] $params
1729          */
1730         public function markParamsSensitive( $params ) {
1731                 $this->mParamsSensitive += array_fill_keys( (array)$params, true );
1732         }
1733
1734         /**
1735          * Get a request value, and register the fact that it was used, for logging.
1736          * @param string $name
1737          * @param string|null $default
1738          * @return string|null
1739          */
1740         public function getVal( $name, $default = null ) {
1741                 $this->mParamsUsed[$name] = true;
1742
1743                 $ret = $this->getRequest()->getVal( $name );
1744                 if ( $ret === null ) {
1745                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1746                                 // See T12262 for why we don't just implode( '|', ... ) the
1747                                 // array.
1748                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1749                         }
1750                         $ret = $default;
1751                 }
1752                 return $ret;
1753         }
1754
1755         /**
1756          * Get a boolean request value, and register the fact that the parameter
1757          * was used, for logging.
1758          * @param string $name
1759          * @return bool
1760          */
1761         public function getCheck( $name ) {
1762                 return $this->getVal( $name, null ) !== null;
1763         }
1764
1765         /**
1766          * Get a request upload, and register the fact that it was used, for logging.
1767          *
1768          * @since 1.21
1769          * @param string $name Parameter name
1770          * @return WebRequestUpload
1771          */
1772         public function getUpload( $name ) {
1773                 $this->mParamsUsed[$name] = true;
1774
1775                 return $this->getRequest()->getUpload( $name );
1776         }
1777
1778         /**
1779          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1780          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1781          */
1782         protected function reportUnusedParams() {
1783                 $paramsUsed = $this->getParamsUsed();
1784                 $allParams = $this->getRequest()->getValueNames();
1785
1786                 if ( !$this->mInternalMode ) {
1787                         // Printer has not yet executed; don't warn that its parameters are unused
1788                         $printerParams = $this->mPrinter->encodeParamName(
1789                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1790                         );
1791                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1792                 } else {
1793                         $unusedParams = array_diff( $allParams, $paramsUsed );
1794                 }
1795
1796                 if ( count( $unusedParams ) ) {
1797                         $this->addWarning( [
1798                                 'apierror-unrecognizedparams',
1799                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1800                                 count( $unusedParams )
1801                         ] );
1802                 }
1803         }
1804
1805         /**
1806          * Print results using the current printer
1807          *
1808          * @param int $httpCode HTTP status code, or 0 to not change
1809          */
1810         protected function printResult( $httpCode = 0 ) {
1811                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1812                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1813                 }
1814
1815                 $printer = $this->mPrinter;
1816                 $printer->initPrinter( false );
1817                 if ( $httpCode ) {
1818                         $printer->setHttpStatus( $httpCode );
1819                 }
1820                 $printer->execute();
1821                 $printer->closePrinter();
1822         }
1823
1824         /**
1825          * @return bool
1826          */
1827         public function isReadMode() {
1828                 return false;
1829         }
1830
1831         /**
1832          * See ApiBase for description.
1833          *
1834          * @return array
1835          */
1836         public function getAllowedParams() {
1837                 return [
1838                         'action' => [
1839                                 ApiBase::PARAM_DFLT => 'help',
1840                                 ApiBase::PARAM_TYPE => 'submodule',
1841                         ],
1842                         'format' => [
1843                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_FORMAT,
1844                                 ApiBase::PARAM_TYPE => 'submodule',
1845                         ],
1846                         'maxlag' => [
1847                                 ApiBase::PARAM_TYPE => 'integer'
1848                         ],
1849                         'smaxage' => [
1850                                 ApiBase::PARAM_TYPE => 'integer',
1851                                 ApiBase::PARAM_DFLT => 0
1852                         ],
1853                         'maxage' => [
1854                                 ApiBase::PARAM_TYPE => 'integer',
1855                                 ApiBase::PARAM_DFLT => 0
1856                         ],
1857                         'assert' => [
1858                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1859                         ],
1860                         'assertuser' => [
1861                                 ApiBase::PARAM_TYPE => 'user',
1862                         ],
1863                         'requestid' => null,
1864                         'servedby' => false,
1865                         'curtimestamp' => false,
1866                         'responselanginfo' => false,
1867                         'origin' => null,
1868                         'uselang' => [
1869                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1870                         ],
1871                         'errorformat' => [
1872                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1873                                 ApiBase::PARAM_DFLT => 'bc',
1874                         ],
1875                         'errorlang' => [
1876                                 ApiBase::PARAM_DFLT => 'uselang',
1877                         ],
1878                         'errorsuselocal' => [
1879                                 ApiBase::PARAM_DFLT => false,
1880                         ],
1881                 ];
1882         }
1883
1884         /** @inheritDoc */
1885         protected function getExamplesMessages() {
1886                 return [
1887                         'action=help'
1888                                 => 'apihelp-help-example-main',
1889                         'action=help&recursivesubmodules=1'
1890                                 => 'apihelp-help-example-recursive',
1891                 ];
1892         }
1893
1894         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1895                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1896                 // reindex the array to get 'permissions' in the right place.
1897                 $oldHelp = $help;
1898                 $help = [];
1899                 foreach ( $oldHelp as $k => $v ) {
1900                         if ( $k === 'submodules' ) {
1901                                 $help['permissions'] = '';
1902                         }
1903                         $help[$k] = $v;
1904                 }
1905                 $help['datatypes'] = '';
1906                 $help['templatedparams'] = '';
1907                 $help['credits'] = '';
1908
1909                 // Fill 'permissions'
1910                 $help['permissions'] .= Html::openElement( 'div',
1911                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1912                 $m = $this->msg( 'api-help-permissions' );
1913                 if ( !$m->isDisabled() ) {
1914                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1915                                 $m->numParams( count( self::$mRights ) )->parse()
1916                         );
1917                 }
1918                 $help['permissions'] .= Html::openElement( 'dl' );
1919                 foreach ( self::$mRights as $right => $rightMsg ) {
1920                         $help['permissions'] .= Html::element( 'dt', null, $right );
1921
1922                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1923                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1924
1925                         $groups = array_map( function ( $group ) {
1926                                 return $group == '*' ? 'all' : $group;
1927                         }, User::getGroupsWithPermission( $right ) );
1928
1929                         $help['permissions'] .= Html::rawElement( 'dd', null,
1930                                 $this->msg( 'api-help-permissions-granted-to' )
1931                                         ->numParams( count( $groups ) )
1932                                         ->params( Message::listParam( $groups ) )
1933                                         ->parse()
1934                         );
1935                 }
1936                 $help['permissions'] .= Html::closeElement( 'dl' );
1937                 $help['permissions'] .= Html::closeElement( 'div' );
1938
1939                 // Fill 'datatypes', 'templatedparams', and 'credits', if applicable
1940                 if ( empty( $options['nolead'] ) ) {
1941                         $level = $options['headerlevel'];
1942                         $tocnumber = &$options['tocnumber'];
1943
1944                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1945
1946                         $id = Sanitizer::escapeIdForAttribute( 'main/datatypes', Sanitizer::ID_PRIMARY );
1947                         $idFallback = Sanitizer::escapeIdForAttribute( 'main/datatypes', Sanitizer::ID_FALLBACK );
1948                         $headline = Linker::makeHeadline( min( 6, $level ),
1949                                 ' class="apihelp-header">',
1950                                 $id,
1951                                 $header,
1952                                 '',
1953                                 $idFallback
1954                         );
1955                         // Ensure we have a sane anchor
1956                         if ( $id !== 'main/datatypes' && $idFallback !== 'main/datatypes' ) {
1957                                 $headline = '<div id="main/datatypes"></div>' . $headline;
1958                         }
1959                         $help['datatypes'] .= $headline;
1960                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1961                         if ( !isset( $tocData['main/datatypes'] ) ) {
1962                                 $tocnumber[$level]++;
1963                                 $tocData['main/datatypes'] = [
1964                                         'toclevel' => count( $tocnumber ),
1965                                         'level' => $level,
1966                                         'anchor' => 'main/datatypes',
1967                                         'line' => $header,
1968                                         'number' => implode( '.', $tocnumber ),
1969                                         'index' => false,
1970                                 ];
1971                         }
1972
1973                         $header = $this->msg( 'api-help-templatedparams-header' )->parse();
1974
1975                         $id = Sanitizer::escapeIdForAttribute( 'main/templatedparams', Sanitizer::ID_PRIMARY );
1976                         $idFallback = Sanitizer::escapeIdForAttribute( 'main/templatedparams', Sanitizer::ID_FALLBACK );
1977                         $headline = Linker::makeHeadline( min( 6, $level ),
1978                                 ' class="apihelp-header">',
1979                                 $id,
1980                                 $header,
1981                                 '',
1982                                 $idFallback
1983                         );
1984                         // Ensure we have a sane anchor
1985                         if ( $id !== 'main/templatedparams' && $idFallback !== 'main/templatedparams' ) {
1986                                 $headline = '<div id="main/templatedparams"></div>' . $headline;
1987                         }
1988                         $help['templatedparams'] .= $headline;
1989                         $help['templatedparams'] .= $this->msg( 'api-help-templatedparams' )->parseAsBlock();
1990                         if ( !isset( $tocData['main/templatedparams'] ) ) {
1991                                 $tocnumber[$level]++;
1992                                 $tocData['main/templatedparams'] = [
1993                                         'toclevel' => count( $tocnumber ),
1994                                         'level' => $level,
1995                                         'anchor' => 'main/templatedparams',
1996                                         'line' => $header,
1997                                         'number' => implode( '.', $tocnumber ),
1998                                         'index' => false,
1999                                 ];
2000                         }
2001
2002                         $header = $this->msg( 'api-credits-header' )->parse();
2003                         $id = Sanitizer::escapeIdForAttribute( 'main/credits', Sanitizer::ID_PRIMARY );
2004                         $idFallback = Sanitizer::escapeIdForAttribute( 'main/credits', Sanitizer::ID_FALLBACK );
2005                         $headline = Linker::makeHeadline( min( 6, $level ),
2006                                 ' class="apihelp-header">',
2007                                 $id,
2008                                 $header,
2009                                 '',
2010                                 $idFallback
2011                         );
2012                         // Ensure we have a sane anchor
2013                         if ( $id !== 'main/credits' && $idFallback !== 'main/credits' ) {
2014                                 $headline = '<div id="main/credits"></div>' . $headline;
2015                         }
2016                         $help['credits'] .= $headline;
2017                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
2018                         if ( !isset( $tocData['main/credits'] ) ) {
2019                                 $tocnumber[$level]++;
2020                                 $tocData['main/credits'] = [
2021                                         'toclevel' => count( $tocnumber ),
2022                                         'level' => $level,
2023                                         'anchor' => 'main/credits',
2024                                         'line' => $header,
2025                                         'number' => implode( '.', $tocnumber ),
2026                                         'index' => false,
2027                                 ];
2028                         }
2029                 }
2030         }
2031
2032         private $mCanApiHighLimits = null;
2033
2034         /**
2035          * Check whether the current user is allowed to use high limits
2036          * @return bool
2037          */
2038         public function canApiHighLimits() {
2039                 if ( !isset( $this->mCanApiHighLimits ) ) {
2040                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
2041                 }
2042
2043                 return $this->mCanApiHighLimits;
2044         }
2045
2046         /**
2047          * Overrides to return this instance's module manager.
2048          * @return ApiModuleManager
2049          */
2050         public function getModuleManager() {
2051                 return $this->mModuleMgr;
2052         }
2053
2054         /**
2055          * Fetches the user agent used for this request
2056          *
2057          * The value will be the combination of the 'Api-User-Agent' header (if
2058          * any) and the standard User-Agent header (if any).
2059          *
2060          * @return string
2061          */
2062         public function getUserAgent() {
2063                 return trim(
2064                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
2065                         $this->getRequest()->getHeader( 'User-agent' )
2066                 );
2067         }
2068 }
2069
2070 /**
2071  * For really cool vim folding this needs to be at the end:
2072  * vim: foldmarker=@{,@} foldmethod=marker
2073  */