includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @defgroup API API
  26  */
  27
  28 use MediaWiki\Logger\LoggerFactory;
  29 use MediaWiki\MediaWikiServices;
  30 use Wikimedia\Timestamp\TimestampException;
  31
  32 /**
  33  * This is the main API class, used for both external and internal processing.
  34  * When executed, it will create the requested formatter object,
  35  * instantiate and execute an object associated with the needed action,
  36  * and use formatter to print results.
  37  * In case of an exception, an error message will be printed using the same formatter.
  38  *
  39  * To use API from another application, run it using FauxRequest object, in which
  40  * case any internal exceptions will not be handled but passed up to the caller.
  41  * After successful execution, use getResult() for the resulting data.
  42  *
  43  * @ingroup API
  44  */
  45 class ApiMain extends ApiBase {
  46         /**
  47          * When no format parameter is given, this format will be used
  48          */
  49         const API_DEFAULT_FORMAT = 'jsonfm';
  50
  51         /**
  52          * When no uselang parameter is given, this language will be used
  53          */
  54         const API_DEFAULT_USELANG = 'user';
  55
  56         /**
  57          * List of available modules: action name => module class
  58          */
  59         private static $Modules = [
  60                 'login' => 'ApiLogin',
  61                 'clientlogin' => 'ApiClientLogin',
  62                 'logout' => 'ApiLogout',
  63                 'createaccount' => 'ApiAMCreateAccount',
  64                 'linkaccount' => 'ApiLinkAccount',
  65                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  66                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  67                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  68                 'resetpassword' => 'ApiResetPassword',
  69                 'query' => 'ApiQuery',
  70                 'expandtemplates' => 'ApiExpandTemplates',
  71                 'parse' => 'ApiParse',
  72                 'stashedit' => 'ApiStashEdit',
  73                 'opensearch' => 'ApiOpenSearch',
  74                 'feedcontributions' => 'ApiFeedContributions',
  75                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  76                 'feedwatchlist' => 'ApiFeedWatchlist',
  77                 'help' => 'ApiHelp',
  78                 'paraminfo' => 'ApiParamInfo',
  79                 'rsd' => 'ApiRsd',
  80                 'compare' => 'ApiComparePages',
  81                 'tokens' => 'ApiTokens',
  82                 'checktoken' => 'ApiCheckToken',
  83                 'cspreport' => 'ApiCSPReport',
  84                 'validatepassword' => 'ApiValidatePassword',
  85
  86                 // Write modules
  87                 'purge' => 'ApiPurge',
  88                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  89                 'rollback' => 'ApiRollback',
  90                 'delete' => 'ApiDelete',
  91                 'undelete' => 'ApiUndelete',
  92                 'protect' => 'ApiProtect',
  93                 'block' => 'ApiBlock',
  94                 'unblock' => 'ApiUnblock',
  95                 'move' => 'ApiMove',
  96                 'edit' => 'ApiEditPage',
  97                 'upload' => 'ApiUpload',
  98                 'filerevert' => 'ApiFileRevert',
  99                 'emailuser' => 'ApiEmailUser',
 100                 'watch' => 'ApiWatch',
 101                 'patrol' => 'ApiPatrol',
 102                 'import' => 'ApiImport',
 103                 'clearhasmsg' => 'ApiClearHasMsg',
 104                 'userrights' => 'ApiUserrights',
 105                 'options' => 'ApiOptions',
 106                 'imagerotate' => 'ApiImageRotate',
 107                 'revisiondelete' => 'ApiRevisionDelete',
 108                 'managetags' => 'ApiManageTags',
 109                 'tag' => 'ApiTag',
 110                 'mergehistory' => 'ApiMergeHistory',
 111                 'setpagelanguage' => 'ApiSetPageLanguage',
 112         ];
 113
 114         /**
 115          * List of available formats: format name => format class
 116          */
 117         private static $Formats = [
 118                 'json' => 'ApiFormatJson',
 119                 'jsonfm' => 'ApiFormatJson',
 120                 'php' => 'ApiFormatPhp',
 121                 'phpfm' => 'ApiFormatPhp',
 122                 'xml' => 'ApiFormatXml',
 123                 'xmlfm' => 'ApiFormatXml',
 124                 'rawfm' => 'ApiFormatJson',
 125                 'none' => 'ApiFormatNone',
 126         ];
 127
 128         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 129         /**
 130          * List of user roles that are specifically relevant to the API.
 131          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 132          *                'params' => [ $someVarToSubst ] ],
 133          * ];
 134          */
 135         private static $mRights = [
 136                 'writeapi' => [
 137                         'msg' => 'right-writeapi',
 138                         'params' => []
 139                 ],
 140                 'apihighlimits' => [
 141                         'msg' => 'api-help-right-apihighlimits',
 142                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 143                 ]
 144         ];
 145         // @codingStandardsIgnoreEnd
 146
 147         /**
 148          * @var ApiFormatBase
 149          */
 150         private $mPrinter;
 151
 152         private $mModuleMgr, $mResult, $mErrorFormatter = null;
 153         /** @var ApiContinuationManager|null */
 154         private $mContinuationManager;
 155         private $mAction;
 156         private $mEnableWrite;
 157         private $mInternalMode, $mSquidMaxage;
 158         /** @var ApiBase */
 159         private $mModule;
 160
 161         private $mCacheMode = 'private';
 162         private $mCacheControl = [];
 163         private $mParamsUsed = [];
 164
 165         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 166         private $lacksSameOriginSecurity = null;
 167
 168         /**
 169          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 170          *
 171          * @param IContextSource|WebRequest $context If this is an instance of
 172          *    FauxRequest, errors are thrown and no printing occurs
 173          * @param bool $enableWrite Should be set to true if the api may modify data
 174          */
 175         public function __construct( $context = null, $enableWrite = false ) {
 176                 if ( $context === null ) {
 177                         $context = RequestContext::getMain();
 178                 } elseif ( $context instanceof WebRequest ) {
 179                         // BC for pre-1.19
 180                         $request = $context;
 181                         $context = RequestContext::getMain();
 182                 }
 183                 // We set a derivative context so we can change stuff later
 184                 $this->setContext( new DerivativeContext( $context ) );
 185
 186                 if ( isset( $request ) ) {
 187                         $this->getContext()->setRequest( $request );
 188                 } else {
 189                         $request = $this->getRequest();
 190                 }
 191
 192                 $this->mInternalMode = ( $request instanceof FauxRequest );
 193
 194                 // Special handling for the main module: $parent === $this
 195                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 196
 197                 $config = $this->getConfig();
 198
 199                 if ( !$this->mInternalMode ) {
 200                         // Log if a request with a non-whitelisted Origin header is seen
 201                         // with session cookies.
 202                         $originHeader = $request->getHeader( 'Origin' );
 203                         if ( $originHeader === false ) {
 204                                 $origins = [];
 205                         } else {
 206                                 $originHeader = trim( $originHeader );
 207                                 $origins = preg_split( '/\s+/', $originHeader );
 208                         }
 209                         $sessionCookies = array_intersect(
 210                                 array_keys( $_COOKIE ),
 211                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 212                         );
 213                         if ( $origins && $sessionCookies && (
 214                                 count( $origins ) !== 1 || !self::matchOrigin(
 215                                         $origins[0],
 216                                         $config->get( 'CrossSiteAJAXdomains' ),
 217                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 218                                 )
 219                         ) ) {
 220                                 LoggerFactory::getInstance( 'cors' )->warning(
 221                                         'Non-whitelisted CORS request with session cookies', [
 222                                                 'origin' => $originHeader,
 223                                                 'cookies' => $sessionCookies,
 224                                                 'ip' => $request->getIP(),
 225                                                 'userAgent' => $this->getUserAgent(),
 226                                                 'wiki' => wfWikiID(),
 227                                         ]
 228                                 );
 229                         }
 230
 231                         // If we're in a mode that breaks the same-origin policy, strip
 232                         // user credentials for security.
 233                         if ( $this->lacksSameOriginSecurity() ) {
 234                                 global $wgUser;
 235                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 236                                 $wgUser = new User();
 237                                 $this->getContext()->setUser( $wgUser );
 238                         }
 239                 }
 240
 241                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 242
 243                 // Setup uselang. This doesn't use $this->getParameter()
 244                 // because we're not ready to handle errors yet.
 245                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 246                 if ( $uselang === 'user' ) {
 247                         // Assume the parent context is going to return the user language
 248                         // for uselang=user (see T85635).
 249                 } else {
 250                         if ( $uselang === 'content' ) {
 251                                 global $wgContLang;
 252                                 $uselang = $wgContLang->getCode();
 253                         }
 254                         $code = RequestContext::sanitizeLangCode( $uselang );
 255                         $this->getContext()->setLanguage( $code );
 256                         if ( !$this->mInternalMode ) {
 257                                 global $wgLang;
 258                                 $wgLang = $this->getContext()->getLanguage();
 259                                 RequestContext::getMain()->setLanguage( $wgLang );
 260                         }
 261                 }
 262
 263                 // Set up the error formatter. This doesn't use $this->getParameter()
 264                 // because we're not ready to handle errors yet.
 265                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 266                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 267                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 268                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 269                         if ( $errorLangCode === 'uselang' ) {
 270                                 $errorLang = $this->getLanguage();
 271                         } elseif ( $errorLangCode === 'content' ) {
 272                                 global $wgContLang;
 273                                 $errorLang = $wgContLang;
 274                         } else {
 275                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 276                                 $errorLang = Language::factory( $errorLangCode );
 277                         }
 278                         $this->mErrorFormatter = new ApiErrorFormatter(
 279                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 280                         );
 281                 } else {
 282                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 283                 }
 284                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 285
 286                 $this->mModuleMgr = new ApiModuleManager( $this );
 287                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 288                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 289                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 290                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 291
 292                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 293
 294                 $this->mContinuationManager = null;
 295                 $this->mEnableWrite = $enableWrite;
 296
 297                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 298                 $this->mCommit = false;
 299         }
 300
 301         /**
 302          * Return true if the API was started by other PHP code using FauxRequest
 303          * @return bool
 304          */
 305         public function isInternalMode() {
 306                 return $this->mInternalMode;
 307         }
 308
 309         /**
 310          * Get the ApiResult object associated with current request
 311          *
 312          * @return ApiResult
 313          */
 314         public function getResult() {
 315                 return $this->mResult;
 316         }
 317
 318         /**
 319          * Get the security flag for the current request
 320          * @return bool
 321          */
 322         public function lacksSameOriginSecurity() {
 323                 if ( $this->lacksSameOriginSecurity !== null ) {
 324                         return $this->lacksSameOriginSecurity;
 325                 }
 326
 327                 $request = $this->getRequest();
 328
 329                 // JSONP mode
 330                 if ( $request->getVal( 'callback' ) !== null ) {
 331                         $this->lacksSameOriginSecurity = true;
 332                         return true;
 333                 }
 334
 335                 // Anonymous CORS
 336                 if ( $request->getVal( 'origin' ) === '*' ) {
 337                         $this->lacksSameOriginSecurity = true;
 338                         return true;
 339                 }
 340
 341                 // Header to be used from XMLHTTPRequest when the request might
 342                 // otherwise be used for XSS.
 343                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 344                         $this->lacksSameOriginSecurity = true;
 345                         return true;
 346                 }
 347
 348                 // Allow extensions to override.
 349                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 350                 return $this->lacksSameOriginSecurity;
 351         }
 352
 353         /**
 354          * Get the ApiErrorFormatter object associated with current request
 355          * @return ApiErrorFormatter
 356          */
 357         public function getErrorFormatter() {
 358                 return $this->mErrorFormatter;
 359         }
 360
 361         /**
 362          * Get the continuation manager
 363          * @return ApiContinuationManager|null
 364          */
 365         public function getContinuationManager() {
 366                 return $this->mContinuationManager;
 367         }
 368
 369         /**
 370          * Set the continuation manager
 371          * @param ApiContinuationManager|null
 372          */
 373         public function setContinuationManager( $manager ) {
 374                 if ( $manager !== null ) {
 375                         if ( !$manager instanceof ApiContinuationManager ) {
 376                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 377                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 378                                 );
 379                         }
 380                         if ( $this->mContinuationManager !== null ) {
 381                                 throw new UnexpectedValueException(
 382                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 383                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 384                                 );
 385                         }
 386                 }
 387                 $this->mContinuationManager = $manager;
 388         }
 389
 390         /**
 391          * Get the API module object. Only works after executeAction()
 392          *
 393          * @return ApiBase
 394          */
 395         public function getModule() {
 396                 return $this->mModule;
 397         }
 398
 399         /**
 400          * Get the result formatter object. Only works after setupExecuteAction()
 401          *
 402          * @return ApiFormatBase
 403          */
 404         public function getPrinter() {
 405                 return $this->mPrinter;
 406         }
 407
 408         /**
 409          * Set how long the response should be cached.
 410          *
 411          * @param int $maxage
 412          */
 413         public function setCacheMaxAge( $maxage ) {
 414                 $this->setCacheControl( [
 415                         'max-age' => $maxage,
 416                         's-maxage' => $maxage
 417                 ] );
 418         }
 419
 420         /**
 421          * Set the type of caching headers which will be sent.
 422          *
 423          * @param string $mode One of:
 424          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 425          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 426          *         not provided by any of these means, the object will be private.
 427          *    - 'private':    Cache this object only in private client-side caches.
 428          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 429          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 430          *         set consistently for a given URL, it cannot be set differently depending on
 431          *         things like the contents of the database, or whether the user is logged in.
 432          *
 433          *  If the wiki does not allow anonymous users to read it, the mode set here
 434          *  will be ignored, and private caching headers will always be sent. In other words,
 435          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 436          *  view.
 437          *
 438          *  For user-dependent data, the private mode should generally be used. The
 439          *  anon-public-user-private mode should only be used where there is a particularly
 440          *  good performance reason for caching the anonymous response, but where the
 441          *  response to logged-in users may differ, or may contain private data.
 442          *
 443          *  If this function is never called, then the default will be the private mode.
 444          */
 445         public function setCacheMode( $mode ) {
 446                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 447                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 448
 449                         // Ignore for forwards-compatibility
 450                         return;
 451                 }
 452
 453                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 454                         // Private wiki, only private headers
 455                         if ( $mode !== 'private' ) {
 456                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 457
 458                                 return;
 459                         }
 460                 }
 461
 462                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 463                         // User language is used for i18n, so we don't want to publicly
 464                         // cache. Anons are ok, because if they have non-default language
 465                         // then there's an appropriate Vary header set by whatever set
 466                         // their non-default language.
 467                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 468                                 "'anon-public-user-private' due to uselang=user\n" );
 469                         $mode = 'anon-public-user-private';
 470                 }
 471
 472                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 473                 $this->mCacheMode = $mode;
 474         }
 475
 476         /**
 477          * Set directives (key/value pairs) for the Cache-Control header.
 478          * Boolean values will be formatted as such, by including or omitting
 479          * without an equals sign.
 480          *
 481          * Cache control values set here will only be used if the cache mode is not
 482          * private, see setCacheMode().
 483          *
 484          * @param array $directives
 485          */
 486         public function setCacheControl( $directives ) {
 487                 $this->mCacheControl = $directives + $this->mCacheControl;
 488         }
 489
 490         /**
 491          * Create an instance of an output formatter by its name
 492          *
 493          * @param string $format
 494          *
 495          * @return ApiFormatBase
 496          */
 497         public function createPrinterByName( $format ) {
 498                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 499                 if ( $printer === null ) {
 500                         $this->dieWithError(
 501                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 502                         );
 503                 }
 504
 505                 return $printer;
 506         }
 507
 508         /**
 509          * Execute api request. Any errors will be handled if the API was called by the remote client.
 510          */
 511         public function execute() {
 512                 if ( $this->mInternalMode ) {
 513                         $this->executeAction();
 514                 } else {
 515                         $this->executeActionWithErrorHandling();
 516                 }
 517         }
 518
 519         /**
 520          * Execute an action, and in case of an error, erase whatever partial results
 521          * have been accumulated, and replace it with an error message and a help screen.
 522          */
 523         protected function executeActionWithErrorHandling() {
 524                 // Verify the CORS header before executing the action
 525                 if ( !$this->handleCORS() ) {
 526                         // handleCORS() has sent a 403, abort
 527                         return;
 528                 }
 529
 530                 // Exit here if the request method was OPTIONS
 531                 // (assume there will be a followup GET or POST)
 532                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 533                         return;
 534                 }
 535
 536                 // In case an error occurs during data output,
 537                 // clear the output buffer and print just the error information
 538                 $obLevel = ob_get_level();
 539                 ob_start();
 540
 541                 $t = microtime( true );
 542                 $isError = false;
 543                 try {
 544                         $this->executeAction();
 545                         $runTime = microtime( true ) - $t;
 546                         $this->logRequest( $runTime );
 547                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 548                                 MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 549                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 550                                 );
 551                         }
 552                 } catch ( Exception $e ) {
 553                         $this->handleException( $e );
 554                         $this->logRequest( microtime( true ) - $t, $e );
 555                         $isError = true;
 556                 }
 557
 558                 // Commit DBs and send any related cookies and headers
 559                 MediaWiki::preOutputCommit( $this->getContext() );
 560
 561                 // Send cache headers after any code which might generate an error, to
 562                 // avoid sending public cache headers for errors.
 563                 $this->sendCacheHeaders( $isError );
 564
 565                 // Executing the action might have already messed with the output
 566                 // buffers.
 567                 while ( ob_get_level() > $obLevel ) {
 568                         ob_end_flush();
 569                 }
 570         }
 571
 572         /**
 573          * Handle an exception as an API response
 574          *
 575          * @since 1.23
 576          * @param Exception $e
 577          */
 578         protected function handleException( Exception $e ) {
 579                 // T65145: Rollback any open database transactions
 580                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 581                         // UsageExceptions are intentional, so don't rollback if that's the case
 582                         try {
 583                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 584                         } catch ( DBError $e2 ) {
 585                                 // Rollback threw an exception too. Log it, but don't interrupt
 586                                 // our regularly scheduled exception handling.
 587                                 MWExceptionHandler::logException( $e2 );
 588                         }
 589                 }
 590
 591                 // Allow extra cleanup and logging
 592                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 593
 594                 // Log it
 595                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 596                         MWExceptionHandler::logException( $e );
 597                 }
 598
 599                 // Handle any kind of exception by outputting properly formatted error message.
 600                 // If this fails, an unhandled exception should be thrown so that global error
 601                 // handler will process and log it.
 602
 603                 $errCodes = $this->substituteResultWithError( $e );
 604
 605                 // Error results should not be cached
 606                 $this->setCacheMode( 'private' );
 607
 608                 $response = $this->getRequest()->response();
 609                 $headerStr = 'MediaWiki-API-Error: ' . join( ', ', $errCodes );
 610                 $response->header( $headerStr );
 611
 612                 // Reset and print just the error message
 613                 ob_clean();
 614
 615                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 616                 $this->createErrorPrinter();
 617
 618                 $failed = false;
 619                 try {
 620                         $this->printResult( $e->getCode() );
 621                 } catch ( ApiUsageException $ex ) {
 622                         // The error printer itself is failing. Try suppressing its request
 623                         // parameters and redo.
 624                         $failed = true;
 625                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 626                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 627                                 try {
 628                                         $this->mPrinter->addWarning( $error );
 629                                 } catch ( Exception $ex2 ) {
 630                                         // WTF?
 631                                         $this->addWarning( $error );
 632                                 }
 633                         }
 634                 } catch ( UsageException $ex ) {
 635                         // The error printer itself is failing. Try suppressing its request
 636                         // parameters and redo.
 637                         $failed = true;
 638                         $this->addWarning(
 639                                 [ 'apiwarn-errorprinterfailed-ex', $ex->getMessage() ], 'errorprinterfailed'
 640                         );
 641                 }
 642                 if ( $failed ) {
 643                         $this->mPrinter = null;
 644                         $this->createErrorPrinter();
 645                         $this->mPrinter->forceDefaultParams();
 646                         if ( $e->getCode() ) {
 647                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 648                         }
 649                         $this->printResult( $e->getCode() );
 650                 }
 651         }
 652
 653         /**
 654          * Handle an exception from the ApiBeforeMain hook.
 655          *
 656          * This tries to print the exception as an API response, to be more
 657          * friendly to clients. If it fails, it will rethrow the exception.
 658          *
 659          * @since 1.23
 660          * @param Exception $e
 661          * @throws Exception
 662          */
 663         public static function handleApiBeforeMainException( Exception $e ) {
 664                 ob_start();
 665
 666                 try {
 667                         $main = new self( RequestContext::getMain(), false );
 668                         $main->handleException( $e );
 669                         $main->logRequest( 0, $e );
 670                 } catch ( Exception $e2 ) {
 671                         // Nope, even that didn't work. Punt.
 672                         throw $e;
 673                 }
 674
 675                 // Reset cache headers
 676                 $main->sendCacheHeaders( true );
 677
 678                 ob_end_flush();
 679         }
 680
 681         /**
 682          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 683          *
 684          * If no origin parameter is present, nothing happens.
 685          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 686          * is set and false is returned.
 687          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 688          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 689          * headers are set.
 690          * https://www.w3.org/TR/cors/#resource-requests
 691          * https://www.w3.org/TR/cors/#resource-preflight-requests
 692          *
 693          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 694          */
 695         protected function handleCORS() {
 696                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 697                 if ( $originParam === null ) {
 698                         // No origin parameter, nothing to do
 699                         return true;
 700                 }
 701
 702                 $request = $this->getRequest();
 703                 $response = $request->response();
 704
 705                 $matchOrigin = false;
 706                 $allowTiming = false;
 707                 $varyOrigin = true;
 708
 709                 if ( $originParam === '*' ) {
 710                         // Request for anonymous CORS
 711                         $matchOrigin = true;
 712                         $allowOrigin = '*';
 713                         $allowCredentials = 'false';
 714                         $varyOrigin = false; // No need to vary
 715                 } else {
 716                         // Non-anonymous CORS, check we allow the domain
 717
 718                         // Origin: header is a space-separated list of origins, check all of them
 719                         $originHeader = $request->getHeader( 'Origin' );
 720                         if ( $originHeader === false ) {
 721                                 $origins = [];
 722                         } else {
 723                                 $originHeader = trim( $originHeader );
 724                                 $origins = preg_split( '/\s+/', $originHeader );
 725                         }
 726
 727                         if ( !in_array( $originParam, $origins ) ) {
 728                                 // origin parameter set but incorrect
 729                                 // Send a 403 response
 730                                 $response->statusHeader( 403 );
 731                                 $response->header( 'Cache-Control: no-cache' );
 732                                 echo "'origin' parameter does not match Origin header\n";
 733
 734                                 return false;
 735                         }
 736
 737                         $config = $this->getConfig();
 738                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 739                                 $originParam,
 740                                 $config->get( 'CrossSiteAJAXdomains' ),
 741                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 742                         );
 743
 744                         $allowOrigin = $originHeader;
 745                         $allowCredentials = 'true';
 746                         $allowTiming = $originHeader;
 747                 }
 748
 749                 if ( $matchOrigin ) {
 750                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 751                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 752                         if ( $preflight ) {
 753                                 // This is a CORS preflight request
 754                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 755                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 756                                         return true;
 757                                 }
 758                                 // We allow the actual request to send the following headers
 759                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 760                                 if ( $requestedHeaders !== false ) {
 761                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 762                                                 return true;
 763                                         }
 764                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 765                                 }
 766
 767                                 // We only allow the actual request to be GET or POST
 768                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 769                         }
 770
 771                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 772                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 773                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 774                         if ( $allowTiming !== false ) {
 775                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 776                         }
 777
 778                         if ( !$preflight ) {
 779                                 $response->header(
 780                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 781                                 );
 782                         }
 783                 }
 784
 785                 if ( $varyOrigin ) {
 786                         $this->getOutput()->addVaryHeader( 'Origin' );
 787                 }
 788
 789                 return true;
 790         }
 791
 792         /**
 793          * Attempt to match an Origin header against a set of rules and a set of exceptions
 794          * @param string $value Origin header
 795          * @param array $rules Set of wildcard rules
 796          * @param array $exceptions Set of wildcard rules
 797          * @return bool True if $value matches a rule in $rules and doesn't match
 798          *    any rules in $exceptions, false otherwise
 799          */
 800         protected static function matchOrigin( $value, $rules, $exceptions ) {
 801                 foreach ( $rules as $rule ) {
 802                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 803                                 // Rule matches, check exceptions
 804                                 foreach ( $exceptions as $exc ) {
 805                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 806                                                 return false;
 807                                         }
 808                                 }
 809
 810                                 return true;
 811                         }
 812                 }
 813
 814                 return false;
 815         }
 816
 817         /**
 818          * Attempt to validate the value of Access-Control-Request-Headers against a list
 819          * of headers that we allow the follow up request to send.
 820          *
 821          * @param string $requestedHeaders Comma seperated list of HTTP headers
 822          * @return bool True if all requested headers are in the list of allowed headers
 823          */
 824         protected static function matchRequestedHeaders( $requestedHeaders ) {
 825                 if ( trim( $requestedHeaders ) === '' ) {
 826                         return true;
 827                 }
 828                 $requestedHeaders = explode( ',', $requestedHeaders );
 829                 $allowedAuthorHeaders = array_flip( [
 830                         /* simple headers (see spec) */
 831                         'accept',
 832                         'accept-language',
 833                         'content-language',
 834                         'content-type',
 835                         /* non-authorable headers in XHR, which are however requested by some UAs */
 836                         'accept-encoding',
 837                         'dnt',
 838                         'origin',
 839                         /* MediaWiki whitelist */
 840                         'api-user-agent',
 841                 ] );
 842                 foreach ( $requestedHeaders as $rHeader ) {
 843                         $rHeader = strtolower( trim( $rHeader ) );
 844                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 845                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 846                                 return false;
 847                         }
 848                 }
 849                 return true;
 850         }
 851
 852         /**
 853          * Helper function to convert wildcard string into a regex
 854          * '*' => '.*?'
 855          * '?' => '.'
 856          *
 857          * @param string $wildcard String with wildcards
 858          * @return string Regular expression
 859          */
 860         protected static function wildcardToRegex( $wildcard ) {
 861                 $wildcard = preg_quote( $wildcard, '/' );
 862                 $wildcard = str_replace(
 863                         [ '\*', '\?' ],
 864                         [ '.*?', '.' ],
 865                         $wildcard
 866                 );
 867
 868                 return "/^https?:\/\/$wildcard$/";
 869         }
 870
 871         /**
 872          * Send caching headers
 873          * @param bool $isError Whether an error response is being output
 874          * @since 1.26 added $isError parameter
 875          */
 876         protected function sendCacheHeaders( $isError ) {
 877                 $response = $this->getRequest()->response();
 878                 $out = $this->getOutput();
 879
 880                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 881
 882                 $config = $this->getConfig();
 883
 884                 if ( $config->get( 'VaryOnXFP' ) ) {
 885                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 886                 }
 887
 888                 if ( !$isError && $this->mModule &&
 889                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 890                 ) {
 891                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 892                         if ( $etag !== null ) {
 893                                 $response->header( "ETag: $etag" );
 894                         }
 895                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 896                         if ( $lastMod !== null ) {
 897                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 898                         }
 899                 }
 900
 901                 // The logic should be:
 902                 // $this->mCacheControl['max-age'] is set?
 903                 //    Use it, the module knows better than our guess.
 904                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 905                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 906                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 907                 $maxage = 0;
 908                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 909                         $maxage = $this->mCacheControl['max-age'];
 910                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 911                         $this->mCacheMode !== 'private'
 912                 ) {
 913                         $maxage = $this->getParameter( 'maxage' );
 914                 }
 915                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 916
 917                 if ( $this->mCacheMode == 'private' ) {
 918                         $response->header( "Cache-Control: $privateCache" );
 919                         return;
 920                 }
 921
 922                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 923                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 924                         $out->addVaryHeader( 'Cookie' );
 925                         $response->header( $out->getVaryHeader() );
 926                         if ( $useKeyHeader ) {
 927                                 $response->header( $out->getKeyHeader() );
 928                                 if ( $out->haveCacheVaryCookies() ) {
 929                                         // Logged in, mark this request private
 930                                         $response->header( "Cache-Control: $privateCache" );
 931                                         return;
 932                                 }
 933                                 // Logged out, send normal public headers below
 934                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 935                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 936                                 // Mark request private
 937                                 $response->header( "Cache-Control: $privateCache" );
 938
 939                                 return;
 940                         } // else no Key and anonymous, send public headers below
 941                 }
 942
 943                 // Send public headers
 944                 $response->header( $out->getVaryHeader() );
 945                 if ( $useKeyHeader ) {
 946                         $response->header( $out->getKeyHeader() );
 947                 }
 948
 949                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 950                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 951                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 952                 }
 953                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 954                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 955                 }
 956
 957                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 958                         // Public cache not requested
 959                         // Sending a Vary header in this case is harmless, and protects us
 960                         // against conditional calls of setCacheMaxAge().
 961                         $response->header( "Cache-Control: $privateCache" );
 962
 963                         return;
 964                 }
 965
 966                 $this->mCacheControl['public'] = true;
 967
 968                 // Send an Expires header
 969                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 970                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 971                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 972
 973                 // Construct the Cache-Control header
 974                 $ccHeader = '';
 975                 $separator = '';
 976                 foreach ( $this->mCacheControl as $name => $value ) {
 977                         if ( is_bool( $value ) ) {
 978                                 if ( $value ) {
 979                                         $ccHeader .= $separator . $name;
 980                                         $separator = ', ';
 981                                 }
 982                         } else {
 983                                 $ccHeader .= $separator . "$name=$value";
 984                                 $separator = ', ';
 985                         }
 986                 }
 987
 988                 $response->header( "Cache-Control: $ccHeader" );
 989         }
 990
 991         /**
 992          * Create the printer for error output
 993          */
 994         private function createErrorPrinter() {
 995                 if ( !isset( $this->mPrinter ) ) {
 996                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 997                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 998                                 $value = self::API_DEFAULT_FORMAT;
 999                         }
1000                         $this->mPrinter = $this->createPrinterByName( $value );
1001                 }
1002
1003                 // Printer may not be able to handle errors. This is particularly
1004                 // likely if the module returns something for getCustomPrinter().
1005                 if ( !$this->mPrinter->canPrintErrors() ) {
1006                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1007                 }
1008         }
1009
1010         /**
1011          * Create an error message for the given exception.
1012          *
1013          * If an ApiUsageException, errors/warnings will be extracted from the
1014          * embedded StatusValue.
1015          *
1016          * If a base UsageException, the getMessageArray() method will be used to
1017          * extract the code and English message for a single error (no warnings).
1018          *
1019          * Any other exception will be returned with a generic code and wrapper
1020          * text around the exception's (presumably English) message as a single
1021          * error (no warnings).
1022          *
1023          * @param Exception $e
1024          * @param string $type 'error' or 'warning'
1025          * @return ApiMessage[]
1026          * @since 1.27
1027          */
1028         protected function errorMessagesFromException( $e, $type = 'error' ) {
1029                 $messages = [];
1030                 if ( $e instanceof ApiUsageException ) {
1031                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1032                                 $messages[] = ApiMessage::create( $error );
1033                         }
1034                 } elseif ( $type !== 'error' ) {
1035                         // None of the rest have any messages for non-error types
1036                 } elseif ( $e instanceof UsageException ) {
1037                         // User entered incorrect parameters - generate error response
1038                         $data = $e->getMessageArray();
1039                         $code = $data['code'];
1040                         $info = $data['info'];
1041                         unset( $data['code'], $data['info'] );
1042                         $messages[] = new ApiRawMessage( [ '$1', $info ], $code, $data );
1043                 } else {
1044                         // Something is seriously wrong
1045                         $config = $this->getConfig();
1046                         $code = 'internal_api_error_' . get_class( $e );
1047                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
1048                                 $params = [ 'apierror-databaseerror', WebRequest::getRequestId() ];
1049                         } else {
1050                                 $params = [
1051                                         'apierror-exceptioncaught',
1052                                         WebRequest::getRequestId(),
1053                                         $e instanceof ILocalizedException
1054                                                 ? $e->getMessageObject()
1055                                                 : wfEscapeWikiText( $e->getMessage() )
1056                                 ];
1057                         }
1058                         $messages[] = ApiMessage::create( $params, $code );
1059                 }
1060                 return $messages;
1061         }
1062
1063         /**
1064          * Replace the result data with the information about an exception.
1065          * @param Exception $e
1066          * @return string[] Error codes
1067          */
1068         protected function substituteResultWithError( $e ) {
1069                 $result = $this->getResult();
1070                 $formatter = $this->getErrorFormatter();
1071                 $config = $this->getConfig();
1072                 $errorCodes = [];
1073
1074                 // Remember existing warnings and errors across the reset
1075                 $errors = $result->getResultData( [ 'errors' ] );
1076                 $warnings = $result->getResultData( [ 'warnings' ] );
1077                 $result->reset();
1078                 if ( $warnings !== null ) {
1079                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1080                 }
1081                 if ( $errors !== null ) {
1082                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1083
1084                         // Collect the copied error codes for the return value
1085                         foreach ( $errors as $error ) {
1086                                 if ( isset( $error['code'] ) ) {
1087                                         $errorCodes[$error['code']] = true;
1088                                 }
1089                         }
1090                 }
1091
1092                 // Add errors from the exception
1093                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1094                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1095                         $errorCodes[$msg->getApiCode()] = true;
1096                         $formatter->addError( $modulePath, $msg );
1097                 }
1098                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1099                         $formatter->addWarning( $modulePath, $msg );
1100                 }
1101
1102                 // Add additional data. Path depends on whether we're in BC mode or not.
1103                 // Data depends on the type of exception.
1104                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1105                         $path = [ 'error' ];
1106                 } else {
1107                         $path = null;
1108                 }
1109                 if ( $e instanceof ApiUsageException || $e instanceof UsageException ) {
1110                         $link = wfExpandUrl( wfScript( 'api' ) );
1111                         $result->addContentValue(
1112                                 $path,
1113                                 'docref',
1114                                 trim(
1115                                         $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1116                                         . ' '
1117                                         . $this->msg( 'api-usage-mailinglist-ref' )->inLanguage( $formatter->getLanguage() )->text()
1118                                 )
1119                         );
1120                 } else {
1121                         if ( $config->get( 'ShowExceptionDetails' ) &&
1122                                 ( !$e instanceof DBError || $config->get( 'ShowDBErrorBacktrace' ) )
1123                         ) {
1124                                 $result->addContentValue(
1125                                         $path,
1126                                         'trace',
1127                                         $this->msg( 'api-exception-trace',
1128                                                 get_class( $e ),
1129                                                 $e->getFile(),
1130                                                 $e->getLine(),
1131                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1132                                         )->inLanguage( $formatter->getLanguage() )->text()
1133                                 );
1134                         }
1135                 }
1136
1137                 // Add the id and such
1138                 $this->addRequestedFields( [ 'servedby' ] );
1139
1140                 return array_keys( $errorCodes );
1141         }
1142
1143         /**
1144          * Add requested fields to the result
1145          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1146          *  - servedby
1147          */
1148         protected function addRequestedFields( $force = [] ) {
1149                 $result = $this->getResult();
1150
1151                 $requestid = $this->getParameter( 'requestid' );
1152                 if ( $requestid !== null ) {
1153                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1154                 }
1155
1156                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1157                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1158                 ) ) {
1159                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1160                 }
1161
1162                 if ( $this->getParameter( 'curtimestamp' ) ) {
1163                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1164                                 ApiResult::NO_SIZE_CHECK );
1165                 }
1166
1167                 if ( $this->getParameter( 'responselanginfo' ) ) {
1168                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1169                                 ApiResult::NO_SIZE_CHECK );
1170                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1171                                 ApiResult::NO_SIZE_CHECK );
1172                 }
1173         }
1174
1175         /**
1176          * Set up for the execution.
1177          * @return array
1178          */
1179         protected function setupExecuteAction() {
1180                 $this->addRequestedFields();
1181
1182                 $params = $this->extractRequestParams();
1183                 $this->mAction = $params['action'];
1184
1185                 return $params;
1186         }
1187
1188         /**
1189          * Set up the module for response
1190          * @return ApiBase The module that will handle this action
1191          * @throws MWException
1192          * @throws ApiUsageException
1193          */
1194         protected function setupModule() {
1195                 // Instantiate the module requested by the user
1196                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1197                 if ( $module === null ) {
1198                         $this->dieWithError(
1199                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1200                         );
1201                 }
1202                 $moduleParams = $module->extractRequestParams();
1203
1204                 // Check token, if necessary
1205                 if ( $module->needsToken() === true ) {
1206                         throw new MWException(
1207                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1208                                 'See documentation for ApiBase::needsToken for details.'
1209                         );
1210                 }
1211                 if ( $module->needsToken() ) {
1212                         if ( !$module->mustBePosted() ) {
1213                                 throw new MWException(
1214                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1215                                 );
1216                         }
1217
1218                         if ( !isset( $moduleParams['token'] ) ) {
1219                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1220                         }
1221
1222                         $module->requirePostedParameters( [ 'token' ] );
1223
1224                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1225                                 $module->dieWithError( 'apierror-badtoken' );
1226                         }
1227                 }
1228
1229                 return $module;
1230         }
1231
1232         /**
1233          * Check the max lag if necessary
1234          * @param ApiBase $module Api module being used
1235          * @param array $params Array an array containing the request parameters.
1236          * @return bool True on success, false should exit immediately
1237          */
1238         protected function checkMaxLag( $module, $params ) {
1239                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1240                         $maxLag = $params['maxlag'];
1241                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1242                         if ( $lag > $maxLag ) {
1243                                 $response = $this->getRequest()->response();
1244
1245                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1246                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1247
1248                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1249                                         $this->dieWithError( [ 'apierror-maxlag', $lag, $host ] );
1250                                 }
1251
1252                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lag ], 'maxlag' );
1253                         }
1254                 }
1255
1256                 return true;
1257         }
1258
1259         /**
1260          * Check selected RFC 7232 precondition headers
1261          *
1262          * RFC 7232 envisions a particular model where you send your request to "a
1263          * resource", and for write requests that you can read "the resource" by
1264          * changing the method to GET. When the API receives a GET request, it
1265          * works out even though "the resource" from RFC 7232's perspective might
1266          * be many resources from MediaWiki's perspective. But it totally fails for
1267          * a POST, since what HTTP sees as "the resource" is probably just
1268          * "/api.php" with all the interesting bits in the body.
1269          *
1270          * Therefore, we only support RFC 7232 precondition headers for GET (and
1271          * HEAD). That means we don't need to bother with If-Match and
1272          * If-Unmodified-Since since they only apply to modification requests.
1273          *
1274          * And since we don't support Range, If-Range is ignored too.
1275          *
1276          * @since 1.26
1277          * @param ApiBase $module Api module being used
1278          * @return bool True on success, false should exit immediately
1279          */
1280         protected function checkConditionalRequestHeaders( $module ) {
1281                 if ( $this->mInternalMode ) {
1282                         // No headers to check in internal mode
1283                         return true;
1284                 }
1285
1286                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1287                         // Don't check POSTs
1288                         return true;
1289                 }
1290
1291                 $return304 = false;
1292
1293                 $ifNoneMatch = array_diff(
1294                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1295                         [ '' ]
1296                 );
1297                 if ( $ifNoneMatch ) {
1298                         if ( $ifNoneMatch === [ '*' ] ) {
1299                                 // API responses always "exist"
1300                                 $etag = '*';
1301                         } else {
1302                                 $etag = $module->getConditionalRequestData( 'etag' );
1303                         }
1304                 }
1305                 if ( $ifNoneMatch && $etag !== null ) {
1306                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1307                         $match = array_map( function ( $s ) {
1308                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1309                         }, $ifNoneMatch );
1310                         $return304 = in_array( $test, $match, true );
1311                 } else {
1312                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1313
1314                         // Some old browsers sends sizes after the date, like this:
1315                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1316                         // Ignore that.
1317                         $i = strpos( $value, ';' );
1318                         if ( $i !== false ) {
1319                                 $value = trim( substr( $value, 0, $i ) );
1320                         }
1321
1322                         if ( $value !== '' ) {
1323                                 try {
1324                                         $ts = new MWTimestamp( $value );
1325                                         if (
1326                                                 // RFC 7231 IMF-fixdate
1327                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1328                                                 // RFC 850
1329                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1330                                                 // asctime (with and without space-padded day)
1331                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1332                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1333                                         ) {
1334                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1335                                                 if ( $lastMod !== null ) {
1336                                                         // Mix in some MediaWiki modification times
1337                                                         $modifiedTimes = [
1338                                                                 'page' => $lastMod,
1339                                                                 'user' => $this->getUser()->getTouched(),
1340                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1341                                                         ];
1342                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1343                                                                 // T46570: the core page itself may not change, but resources might
1344                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1345                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1346                                                                 );
1347                                                         }
1348                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1349                                                         $lastMod = max( $modifiedTimes );
1350                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1351                                                 }
1352                                         }
1353                                 } catch ( TimestampException $e ) {
1354                                         // Invalid timestamp, ignore it
1355                                 }
1356                         }
1357                 }
1358
1359                 if ( $return304 ) {
1360                         $this->getRequest()->response()->statusHeader( 304 );
1361
1362                         // Avoid outputting the compressed representation of a zero-length body
1363                         MediaWiki\suppressWarnings();
1364                         ini_set( 'zlib.output_compression', 0 );
1365                         MediaWiki\restoreWarnings();
1366                         wfClearOutputBuffers();
1367
1368                         return false;
1369                 }
1370
1371                 return true;
1372         }
1373
1374         /**
1375          * Check for sufficient permissions to execute
1376          * @param ApiBase $module An Api module
1377          */
1378         protected function checkExecutePermissions( $module ) {
1379                 $user = $this->getUser();
1380                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1381                         !$user->isAllowed( 'read' )
1382                 ) {
1383                         $this->dieWithError( 'apierror-readapidenied' );
1384                 }
1385
1386                 if ( $module->isWriteMode() ) {
1387                         if ( !$this->mEnableWrite ) {
1388                                 $this->dieWithError( 'apierror-noapiwrite' );
1389                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1390                                 $this->dieWithError( 'apierror-writeapidenied' );
1391                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1392                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1393                         }
1394
1395                         $this->checkReadOnly( $module );
1396                 }
1397
1398                 // Allow extensions to stop execution for arbitrary reasons.
1399                 $message = false;
1400                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1401                         $this->dieWithError( $message );
1402                 }
1403         }
1404
1405         /**
1406          * Check if the DB is read-only for this user
1407          * @param ApiBase $module An Api module
1408          */
1409         protected function checkReadOnly( $module ) {
1410                 if ( wfReadOnly() ) {
1411                         $this->dieReadOnly();
1412                 }
1413
1414                 if ( $module->isWriteMode()
1415                         && $this->getUser()->isBot()
1416                         && wfGetLB()->getServerCount() > 1
1417                 ) {
1418                         $this->checkBotReadOnly();
1419                 }
1420         }
1421
1422         /**
1423          * Check whether we are readonly for bots
1424          */
1425         private function checkBotReadOnly() {
1426                 // Figure out how many servers have passed the lag threshold
1427                 $numLagged = 0;
1428                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1429                 $laggedServers = [];
1430                 $loadBalancer = wfGetLB();
1431                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1432                         if ( $lag > $lagLimit ) {
1433                                 ++$numLagged;
1434                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1435                         }
1436                 }
1437
1438                 // If a majority of replica DBs are too lagged then disallow writes
1439                 $replicaCount = wfGetLB()->getServerCount() - 1;
1440                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1441                         $laggedServers = implode( ', ', $laggedServers );
1442                         wfDebugLog(
1443                                 'api-readonly',
1444                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1445                         );
1446
1447                         $this->dieWithError(
1448                                 'readonly_lag',
1449                                 'readonly',
1450                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1451                         );
1452                 }
1453         }
1454
1455         /**
1456          * Check asserts of the user's rights
1457          * @param array $params
1458          */
1459         protected function checkAsserts( $params ) {
1460                 if ( isset( $params['assert'] ) ) {
1461                         $user = $this->getUser();
1462                         switch ( $params['assert'] ) {
1463                                 case 'user':
1464                                         if ( $user->isAnon() ) {
1465                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1466                                         }
1467                                         break;
1468                                 case 'bot':
1469                                         if ( !$user->isAllowed( 'bot' ) ) {
1470                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1471                                         }
1472                                         break;
1473                         }
1474                 }
1475                 if ( isset( $params['assertuser'] ) ) {
1476                         $assertUser = User::newFromName( $params['assertuser'], false );
1477                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1478                                 $this->dieWithError(
1479                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1480                                 );
1481                         }
1482                 }
1483         }
1484
1485         /**
1486          * Check POST for external response and setup result printer
1487          * @param ApiBase $module An Api module
1488          * @param array $params An array with the request parameters
1489          */
1490         protected function setupExternalResponse( $module, $params ) {
1491                 $request = $this->getRequest();
1492                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1493                         // Module requires POST. GET request might still be allowed
1494                         // if $wgDebugApi is true, otherwise fail.
1495                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1496                 }
1497
1498                 // See if custom printer is used
1499                 $this->mPrinter = $module->getCustomPrinter();
1500                 if ( is_null( $this->mPrinter ) ) {
1501                         // Create an appropriate printer
1502                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1503                 }
1504
1505                 if ( $request->getProtocol() === 'http' && (
1506                         $request->getSession()->shouldForceHTTPS() ||
1507                         ( $this->getUser()->isLoggedIn() &&
1508                                 $this->getUser()->requiresHTTPS() )
1509                 ) ) {
1510                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1511                 }
1512         }
1513
1514         /**
1515          * Execute the actual module, without any error handling
1516          */
1517         protected function executeAction() {
1518                 $params = $this->setupExecuteAction();
1519                 $module = $this->setupModule();
1520                 $this->mModule = $module;
1521
1522                 if ( !$this->mInternalMode ) {
1523                         $this->setRequestExpectations( $module );
1524                 }
1525
1526                 $this->checkExecutePermissions( $module );
1527
1528                 if ( !$this->checkMaxLag( $module, $params ) ) {
1529                         return;
1530                 }
1531
1532                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1533                         return;
1534                 }
1535
1536                 if ( !$this->mInternalMode ) {
1537                         $this->setupExternalResponse( $module, $params );
1538                 }
1539
1540                 $this->checkAsserts( $params );
1541
1542                 // Execute
1543                 $module->execute();
1544                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1545
1546                 $this->reportUnusedParams();
1547
1548                 if ( !$this->mInternalMode ) {
1549                         // append Debug information
1550                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1551
1552                         // Print result data
1553                         $this->printResult();
1554                 }
1555         }
1556
1557         /**
1558          * Set database connection, query, and write expectations given this module request
1559          * @param ApiBase $module
1560          */
1561         protected function setRequestExpectations( ApiBase $module ) {
1562                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1563                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1564                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1565                 if ( $this->getRequest()->hasSafeMethod() ) {
1566                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1567                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1568                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1569                         $this->getRequest()->markAsSafeRequest();
1570                 } else {
1571                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1572                 }
1573         }
1574
1575         /**
1576          * Log the preceding request
1577          * @param float $time Time in seconds
1578          * @param Exception $e Exception caught while processing the request
1579          */
1580         protected function logRequest( $time, $e = null ) {
1581                 $request = $this->getRequest();
1582                 $logCtx = [
1583                         'ts' => time(),
1584                         'ip' => $request->getIP(),
1585                         'userAgent' => $this->getUserAgent(),
1586                         'wiki' => wfWikiID(),
1587                         'timeSpentBackend' => (int)round( $time * 1000 ),
1588                         'hadError' => $e !== null,
1589                         'errorCodes' => [],
1590                         'params' => [],
1591                 ];
1592
1593                 if ( $e ) {
1594                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1595                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1596                         }
1597                 }
1598
1599                 // Construct space separated message for 'api' log channel
1600                 $msg = "API {$request->getMethod()} " .
1601                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1602                         " {$logCtx['ip']} " .
1603                         "T={$logCtx['timeSpentBackend']}ms";
1604
1605                 foreach ( $this->getParamsUsed() as $name ) {
1606                         $value = $request->getVal( $name );
1607                         if ( $value === null ) {
1608                                 continue;
1609                         }
1610
1611                         if ( strlen( $value ) > 256 ) {
1612                                 $value = substr( $value, 0, 256 );
1613                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1614                         } else {
1615                                 $encValue = $this->encodeRequestLogValue( $value );
1616                         }
1617
1618                         $logCtx['params'][$name] = $value;
1619                         $msg .= " {$name}={$encValue}";
1620                 }
1621
1622                 wfDebugLog( 'api', $msg, 'private' );
1623                 // ApiAction channel is for structured data consumers
1624                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1625         }
1626
1627         /**
1628          * Encode a value in a format suitable for a space-separated log line.
1629          * @param string $s
1630          * @return string
1631          */
1632         protected function encodeRequestLogValue( $s ) {
1633                 static $table;
1634                 if ( !$table ) {
1635                         $chars = ';@$!*(),/:';
1636                         $numChars = strlen( $chars );
1637                         for ( $i = 0; $i < $numChars; $i++ ) {
1638                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1639                         }
1640                 }
1641
1642                 return strtr( rawurlencode( $s ), $table );
1643         }
1644
1645         /**
1646          * Get the request parameters used in the course of the preceding execute() request
1647          * @return array
1648          */
1649         protected function getParamsUsed() {
1650                 return array_keys( $this->mParamsUsed );
1651         }
1652
1653         /**
1654          * Mark parameters as used
1655          * @param string|string[] $params
1656          */
1657         public function markParamsUsed( $params ) {
1658                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1659         }
1660
1661         /**
1662          * Get a request value, and register the fact that it was used, for logging.
1663          * @param string $name
1664          * @param mixed $default
1665          * @return mixed
1666          */
1667         public function getVal( $name, $default = null ) {
1668                 $this->mParamsUsed[$name] = true;
1669
1670                 $ret = $this->getRequest()->getVal( $name );
1671                 if ( $ret === null ) {
1672                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1673                                 // See T12262 for why we don't just implode( '|', ... ) the
1674                                 // array.
1675                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1676                         }
1677                         $ret = $default;
1678                 }
1679                 return $ret;
1680         }
1681
1682         /**
1683          * Get a boolean request value, and register the fact that the parameter
1684          * was used, for logging.
1685          * @param string $name
1686          * @return bool
1687          */
1688         public function getCheck( $name ) {
1689                 return $this->getVal( $name, null ) !== null;
1690         }
1691
1692         /**
1693          * Get a request upload, and register the fact that it was used, for logging.
1694          *
1695          * @since 1.21
1696          * @param string $name Parameter name
1697          * @return WebRequestUpload
1698          */
1699         public function getUpload( $name ) {
1700                 $this->mParamsUsed[$name] = true;
1701
1702                 return $this->getRequest()->getUpload( $name );
1703         }
1704
1705         /**
1706          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1707          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1708          */
1709         protected function reportUnusedParams() {
1710                 $paramsUsed = $this->getParamsUsed();
1711                 $allParams = $this->getRequest()->getValueNames();
1712
1713                 if ( !$this->mInternalMode ) {
1714                         // Printer has not yet executed; don't warn that its parameters are unused
1715                         $printerParams = $this->mPrinter->encodeParamName(
1716                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1717                         );
1718                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1719                 } else {
1720                         $unusedParams = array_diff( $allParams, $paramsUsed );
1721                 }
1722
1723                 if ( count( $unusedParams ) ) {
1724                         $this->addWarning( [
1725                                 'apierror-unrecognizedparams',
1726                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1727                                 count( $unusedParams )
1728                         ] );
1729                 }
1730         }
1731
1732         /**
1733          * Print results using the current printer
1734          *
1735          * @param int $httpCode HTTP status code, or 0 to not change
1736          */
1737         protected function printResult( $httpCode = 0 ) {
1738                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1739                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1740                 }
1741
1742                 $printer = $this->mPrinter;
1743                 $printer->initPrinter( false );
1744                 if ( $httpCode ) {
1745                         $printer->setHttpStatus( $httpCode );
1746                 }
1747                 $printer->execute();
1748                 $printer->closePrinter();
1749         }
1750
1751         /**
1752          * @return bool
1753          */
1754         public function isReadMode() {
1755                 return false;
1756         }
1757
1758         /**
1759          * See ApiBase for description.
1760          *
1761          * @return array
1762          */
1763         public function getAllowedParams() {
1764                 return [
1765                         'action' => [
1766                                 ApiBase::PARAM_DFLT => 'help',
1767                                 ApiBase::PARAM_TYPE => 'submodule',
1768                         ],
1769                         'format' => [
1770                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1771                                 ApiBase::PARAM_TYPE => 'submodule',
1772                         ],
1773                         'maxlag' => [
1774                                 ApiBase::PARAM_TYPE => 'integer'
1775                         ],
1776                         'smaxage' => [
1777                                 ApiBase::PARAM_TYPE => 'integer',
1778                                 ApiBase::PARAM_DFLT => 0
1779                         ],
1780                         'maxage' => [
1781                                 ApiBase::PARAM_TYPE => 'integer',
1782                                 ApiBase::PARAM_DFLT => 0
1783                         ],
1784                         'assert' => [
1785                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1786                         ],
1787                         'assertuser' => [
1788                                 ApiBase::PARAM_TYPE => 'user',
1789                         ],
1790                         'requestid' => null,
1791                         'servedby' => false,
1792                         'curtimestamp' => false,
1793                         'responselanginfo' => false,
1794                         'origin' => null,
1795                         'uselang' => [
1796                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1797                         ],
1798                         'errorformat' => [
1799                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1800                                 ApiBase::PARAM_DFLT => 'bc',
1801                         ],
1802                         'errorlang' => [
1803                                 ApiBase::PARAM_DFLT => 'uselang',
1804                         ],
1805                         'errorsuselocal' => [
1806                                 ApiBase::PARAM_DFLT => false,
1807                         ],
1808                 ];
1809         }
1810
1811         /** @see ApiBase::getExamplesMessages() */
1812         protected function getExamplesMessages() {
1813                 return [
1814                         'action=help'
1815                                 => 'apihelp-help-example-main',
1816                         'action=help&recursivesubmodules=1'
1817                                 => 'apihelp-help-example-recursive',
1818                 ];
1819         }
1820
1821         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1822                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1823                 // reindex the array to get 'permissions' in the right place.
1824                 $oldHelp = $help;
1825                 $help = [];
1826                 foreach ( $oldHelp as $k => $v ) {
1827                         if ( $k === 'submodules' ) {
1828                                 $help['permissions'] = '';
1829                         }
1830                         $help[$k] = $v;
1831                 }
1832                 $help['datatypes'] = '';
1833                 $help['credits'] = '';
1834
1835                 // Fill 'permissions'
1836                 $help['permissions'] .= Html::openElement( 'div',
1837                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1838                 $m = $this->msg( 'api-help-permissions' );
1839                 if ( !$m->isDisabled() ) {
1840                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1841                                 $m->numParams( count( self::$mRights ) )->parse()
1842                         );
1843                 }
1844                 $help['permissions'] .= Html::openElement( 'dl' );
1845                 foreach ( self::$mRights as $right => $rightMsg ) {
1846                         $help['permissions'] .= Html::element( 'dt', null, $right );
1847
1848                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1849                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1850
1851                         $groups = array_map( function ( $group ) {
1852                                 return $group == '*' ? 'all' : $group;
1853                         }, User::getGroupsWithPermission( $right ) );
1854
1855                         $help['permissions'] .= Html::rawElement( 'dd', null,
1856                                 $this->msg( 'api-help-permissions-granted-to' )
1857                                         ->numParams( count( $groups ) )
1858                                         ->params( Message::listParam( $groups ) )
1859                                         ->parse()
1860                         );
1861                 }
1862                 $help['permissions'] .= Html::closeElement( 'dl' );
1863                 $help['permissions'] .= Html::closeElement( 'div' );
1864
1865                 // Fill 'datatypes' and 'credits', if applicable
1866                 if ( empty( $options['nolead'] ) ) {
1867                         $level = $options['headerlevel'];
1868                         $tocnumber = &$options['tocnumber'];
1869
1870                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1871
1872                         // Add an additional span with sanitized ID
1873                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1874                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1875                                         $header;
1876                         }
1877                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1878                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1879                                 $header
1880                         );
1881                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1882                         if ( !isset( $tocData['main/datatypes'] ) ) {
1883                                 $tocnumber[$level]++;
1884                                 $tocData['main/datatypes'] = [
1885                                         'toclevel' => count( $tocnumber ),
1886                                         'level' => $level,
1887                                         'anchor' => 'main/datatypes',
1888                                         'line' => $header,
1889                                         'number' => implode( '.', $tocnumber ),
1890                                         'index' => false,
1891                                 ];
1892                         }
1893
1894                         // Add an additional span with sanitized ID
1895                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1896                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1897                                         $header;
1898                         }
1899                         $header = $this->msg( 'api-credits-header' )->parse();
1900                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1901                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1902                                 $header
1903                         );
1904                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1905                         if ( !isset( $tocData['main/credits'] ) ) {
1906                                 $tocnumber[$level]++;
1907                                 $tocData['main/credits'] = [
1908                                         'toclevel' => count( $tocnumber ),
1909                                         'level' => $level,
1910                                         'anchor' => 'main/credits',
1911                                         'line' => $header,
1912                                         'number' => implode( '.', $tocnumber ),
1913                                         'index' => false,
1914                                 ];
1915                         }
1916                 }
1917         }
1918
1919         private $mCanApiHighLimits = null;
1920
1921         /**
1922          * Check whether the current user is allowed to use high limits
1923          * @return bool
1924          */
1925         public function canApiHighLimits() {
1926                 if ( !isset( $this->mCanApiHighLimits ) ) {
1927                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1928                 }
1929
1930                 return $this->mCanApiHighLimits;
1931         }
1932
1933         /**
1934          * Overrides to return this instance's module manager.
1935          * @return ApiModuleManager
1936          */
1937         public function getModuleManager() {
1938                 return $this->mModuleMgr;
1939         }
1940
1941         /**
1942          * Fetches the user agent used for this request
1943          *
1944          * The value will be the combination of the 'Api-User-Agent' header (if
1945          * any) and the standard User-Agent header (if any).
1946          *
1947          * @return string
1948          */
1949         public function getUserAgent() {
1950                 return trim(
1951                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1952                         $this->getRequest()->getHeader( 'User-agent' )
1953                 );
1954         }
1955 }
1956
1957 /**
1958  * For really cool vim folding this needs to be at the end:
1959  * vim: foldmarker=@{,@} foldmethod=marker
1960  */