includes/api/ApiMain.php

   1 <?php
   2 /**
   3  * Created on Sep 4, 2006
   4  *
   5  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  * @defgroup API API
  24  */
  25
  26 use MediaWiki\Logger\LoggerFactory;
  27 use MediaWiki\MediaWikiServices;
  28 use Wikimedia\Timestamp\TimestampException;
  29 use Wikimedia\Rdbms\DBQueryError;
  30 use Wikimedia\Rdbms\DBError;
  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         private $mParamsSensitive = [];
 165
 166         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 167         private $lacksSameOriginSecurity = null;
 168
 169         /**
 170          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 171          *
 172          * @param IContextSource|WebRequest $context If this is an instance of
 173          *    FauxRequest, errors are thrown and no printing occurs
 174          * @param bool $enableWrite Should be set to true if the api may modify data
 175          */
 176         public function __construct( $context = null, $enableWrite = false ) {
 177                 if ( $context === null ) {
 178                         $context = RequestContext::getMain();
 179                 } elseif ( $context instanceof WebRequest ) {
 180                         // BC for pre-1.19
 181                         $request = $context;
 182                         $context = RequestContext::getMain();
 183                 }
 184                 // We set a derivative context so we can change stuff later
 185                 $this->setContext( new DerivativeContext( $context ) );
 186
 187                 if ( isset( $request ) ) {
 188                         $this->getContext()->setRequest( $request );
 189                 } else {
 190                         $request = $this->getRequest();
 191                 }
 192
 193                 $this->mInternalMode = ( $request instanceof FauxRequest );
 194
 195                 // Special handling for the main module: $parent === $this
 196                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 197
 198                 $config = $this->getConfig();
 199
 200                 if ( !$this->mInternalMode ) {
 201                         // Log if a request with a non-whitelisted Origin header is seen
 202                         // with session cookies.
 203                         $originHeader = $request->getHeader( 'Origin' );
 204                         if ( $originHeader === false ) {
 205                                 $origins = [];
 206                         } else {
 207                                 $originHeader = trim( $originHeader );
 208                                 $origins = preg_split( '/\s+/', $originHeader );
 209                         }
 210                         $sessionCookies = array_intersect(
 211                                 array_keys( $_COOKIE ),
 212                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 213                         );
 214                         if ( $origins && $sessionCookies && (
 215                                 count( $origins ) !== 1 || !self::matchOrigin(
 216                                         $origins[0],
 217                                         $config->get( 'CrossSiteAJAXdomains' ),
 218                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 219                                 )
 220                         ) ) {
 221                                 LoggerFactory::getInstance( 'cors' )->warning(
 222                                         'Non-whitelisted CORS request with session cookies', [
 223                                                 'origin' => $originHeader,
 224                                                 'cookies' => $sessionCookies,
 225                                                 'ip' => $request->getIP(),
 226                                                 'userAgent' => $this->getUserAgent(),
 227                                                 'wiki' => wfWikiID(),
 228                                         ]
 229                                 );
 230                         }
 231
 232                         // If we're in a mode that breaks the same-origin policy, strip
 233                         // user credentials for security.
 234                         if ( $this->lacksSameOriginSecurity() ) {
 235                                 global $wgUser;
 236                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 237                                 $wgUser = new User();
 238                                 $this->getContext()->setUser( $wgUser );
 239                                 $request->response()->header( 'MediaWiki-Login-Suppressed: true' );
 240                         }
 241                 }
 242
 243                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 244
 245                 // Setup uselang. This doesn't use $this->getParameter()
 246                 // because we're not ready to handle errors yet.
 247                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 248                 if ( $uselang === 'user' ) {
 249                         // Assume the parent context is going to return the user language
 250                         // for uselang=user (see T85635).
 251                 } else {
 252                         if ( $uselang === 'content' ) {
 253                                 global $wgContLang;
 254                                 $uselang = $wgContLang->getCode();
 255                         }
 256                         $code = RequestContext::sanitizeLangCode( $uselang );
 257                         $this->getContext()->setLanguage( $code );
 258                         if ( !$this->mInternalMode ) {
 259                                 global $wgLang;
 260                                 $wgLang = $this->getContext()->getLanguage();
 261                                 RequestContext::getMain()->setLanguage( $wgLang );
 262                         }
 263                 }
 264
 265                 // Set up the error formatter. This doesn't use $this->getParameter()
 266                 // because we're not ready to handle errors yet.
 267                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 268                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 269                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 270                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 271                         if ( $errorLangCode === 'uselang' ) {
 272                                 $errorLang = $this->getLanguage();
 273                         } elseif ( $errorLangCode === 'content' ) {
 274                                 global $wgContLang;
 275                                 $errorLang = $wgContLang;
 276                         } else {
 277                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 278                                 $errorLang = Language::factory( $errorLangCode );
 279                         }
 280                         $this->mErrorFormatter = new ApiErrorFormatter(
 281                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 282                         );
 283                 } else {
 284                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 285                 }
 286                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 287
 288                 $this->mModuleMgr = new ApiModuleManager( $this );
 289                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 290                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 291                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 292                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 293
 294                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 295
 296                 $this->mContinuationManager = null;
 297                 $this->mEnableWrite = $enableWrite;
 298
 299                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 300                 $this->mCommit = false;
 301         }
 302
 303         /**
 304          * Return true if the API was started by other PHP code using FauxRequest
 305          * @return bool
 306          */
 307         public function isInternalMode() {
 308                 return $this->mInternalMode;
 309         }
 310
 311         /**
 312          * Get the ApiResult object associated with current request
 313          *
 314          * @return ApiResult
 315          */
 316         public function getResult() {
 317                 return $this->mResult;
 318         }
 319
 320         /**
 321          * Get the security flag for the current request
 322          * @return bool
 323          */
 324         public function lacksSameOriginSecurity() {
 325                 if ( $this->lacksSameOriginSecurity !== null ) {
 326                         return $this->lacksSameOriginSecurity;
 327                 }
 328
 329                 $request = $this->getRequest();
 330
 331                 // JSONP mode
 332                 if ( $request->getVal( 'callback' ) !== null ) {
 333                         $this->lacksSameOriginSecurity = true;
 334                         return true;
 335                 }
 336
 337                 // Anonymous CORS
 338                 if ( $request->getVal( 'origin' ) === '*' ) {
 339                         $this->lacksSameOriginSecurity = true;
 340                         return true;
 341                 }
 342
 343                 // Header to be used from XMLHTTPRequest when the request might
 344                 // otherwise be used for XSS.
 345                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 346                         $this->lacksSameOriginSecurity = true;
 347                         return true;
 348                 }
 349
 350                 // Allow extensions to override.
 351                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 352                 return $this->lacksSameOriginSecurity;
 353         }
 354
 355         /**
 356          * Get the ApiErrorFormatter object associated with current request
 357          * @return ApiErrorFormatter
 358          */
 359         public function getErrorFormatter() {
 360                 return $this->mErrorFormatter;
 361         }
 362
 363         /**
 364          * Get the continuation manager
 365          * @return ApiContinuationManager|null
 366          */
 367         public function getContinuationManager() {
 368                 return $this->mContinuationManager;
 369         }
 370
 371         /**
 372          * Set the continuation manager
 373          * @param ApiContinuationManager|null
 374          */
 375         public function setContinuationManager( $manager ) {
 376                 if ( $manager !== null ) {
 377                         if ( !$manager instanceof ApiContinuationManager ) {
 378                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 379                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 380                                 );
 381                         }
 382                         if ( $this->mContinuationManager !== null ) {
 383                                 throw new UnexpectedValueException(
 384                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 385                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 386                                 );
 387                         }
 388                 }
 389                 $this->mContinuationManager = $manager;
 390         }
 391
 392         /**
 393          * Get the API module object. Only works after executeAction()
 394          *
 395          * @return ApiBase
 396          */
 397         public function getModule() {
 398                 return $this->mModule;
 399         }
 400
 401         /**
 402          * Get the result formatter object. Only works after setupExecuteAction()
 403          *
 404          * @return ApiFormatBase
 405          */
 406         public function getPrinter() {
 407                 return $this->mPrinter;
 408         }
 409
 410         /**
 411          * Set how long the response should be cached.
 412          *
 413          * @param int $maxage
 414          */
 415         public function setCacheMaxAge( $maxage ) {
 416                 $this->setCacheControl( [
 417                         'max-age' => $maxage,
 418                         's-maxage' => $maxage
 419                 ] );
 420         }
 421
 422         /**
 423          * Set the type of caching headers which will be sent.
 424          *
 425          * @param string $mode One of:
 426          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 427          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 428          *         not provided by any of these means, the object will be private.
 429          *    - 'private':    Cache this object only in private client-side caches.
 430          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 431          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 432          *         set consistently for a given URL, it cannot be set differently depending on
 433          *         things like the contents of the database, or whether the user is logged in.
 434          *
 435          *  If the wiki does not allow anonymous users to read it, the mode set here
 436          *  will be ignored, and private caching headers will always be sent. In other words,
 437          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 438          *  view.
 439          *
 440          *  For user-dependent data, the private mode should generally be used. The
 441          *  anon-public-user-private mode should only be used where there is a particularly
 442          *  good performance reason for caching the anonymous response, but where the
 443          *  response to logged-in users may differ, or may contain private data.
 444          *
 445          *  If this function is never called, then the default will be the private mode.
 446          */
 447         public function setCacheMode( $mode ) {
 448                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 449                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 450
 451                         // Ignore for forwards-compatibility
 452                         return;
 453                 }
 454
 455                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 456                         // Private wiki, only private headers
 457                         if ( $mode !== 'private' ) {
 458                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 459
 460                                 return;
 461                         }
 462                 }
 463
 464                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 465                         // User language is used for i18n, so we don't want to publicly
 466                         // cache. Anons are ok, because if they have non-default language
 467                         // then there's an appropriate Vary header set by whatever set
 468                         // their non-default language.
 469                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 470                                 "'anon-public-user-private' due to uselang=user\n" );
 471                         $mode = 'anon-public-user-private';
 472                 }
 473
 474                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 475                 $this->mCacheMode = $mode;
 476         }
 477
 478         /**
 479          * Set directives (key/value pairs) for the Cache-Control header.
 480          * Boolean values will be formatted as such, by including or omitting
 481          * without an equals sign.
 482          *
 483          * Cache control values set here will only be used if the cache mode is not
 484          * private, see setCacheMode().
 485          *
 486          * @param array $directives
 487          */
 488         public function setCacheControl( $directives ) {
 489                 $this->mCacheControl = $directives + $this->mCacheControl;
 490         }
 491
 492         /**
 493          * Create an instance of an output formatter by its name
 494          *
 495          * @param string $format
 496          *
 497          * @return ApiFormatBase
 498          */
 499         public function createPrinterByName( $format ) {
 500                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 501                 if ( $printer === null ) {
 502                         $this->dieWithError(
 503                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 504                         );
 505                 }
 506
 507                 return $printer;
 508         }
 509
 510         /**
 511          * Execute api request. Any errors will be handled if the API was called by the remote client.
 512          */
 513         public function execute() {
 514                 if ( $this->mInternalMode ) {
 515                         $this->executeAction();
 516                 } else {
 517                         $this->executeActionWithErrorHandling();
 518                 }
 519         }
 520
 521         /**
 522          * Execute an action, and in case of an error, erase whatever partial results
 523          * have been accumulated, and replace it with an error message and a help screen.
 524          */
 525         protected function executeActionWithErrorHandling() {
 526                 // Verify the CORS header before executing the action
 527                 if ( !$this->handleCORS() ) {
 528                         // handleCORS() has sent a 403, abort
 529                         return;
 530                 }
 531
 532                 // Exit here if the request method was OPTIONS
 533                 // (assume there will be a followup GET or POST)
 534                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 535                         return;
 536                 }
 537
 538                 // In case an error occurs during data output,
 539                 // clear the output buffer and print just the error information
 540                 $obLevel = ob_get_level();
 541                 ob_start();
 542
 543                 $t = microtime( true );
 544                 $isError = false;
 545                 try {
 546                         $this->executeAction();
 547                         $runTime = microtime( true ) - $t;
 548                         $this->logRequest( $runTime );
 549                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 550                                 MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 551                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 552                                 );
 553                         }
 554                 } catch ( Exception $e ) {
 555                         $this->handleException( $e );
 556                         $this->logRequest( microtime( true ) - $t, $e );
 557                         $isError = true;
 558                 }
 559
 560                 // Commit DBs and send any related cookies and headers
 561                 MediaWiki::preOutputCommit( $this->getContext() );
 562
 563                 // Send cache headers after any code which might generate an error, to
 564                 // avoid sending public cache headers for errors.
 565                 $this->sendCacheHeaders( $isError );
 566
 567                 // Executing the action might have already messed with the output
 568                 // buffers.
 569                 while ( ob_get_level() > $obLevel ) {
 570                         ob_end_flush();
 571                 }
 572         }
 573
 574         /**
 575          * Handle an exception as an API response
 576          *
 577          * @since 1.23
 578          * @param Exception $e
 579          */
 580         protected function handleException( Exception $e ) {
 581                 // T65145: Rollback any open database transactions
 582                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 583                         // UsageExceptions are intentional, so don't rollback if that's the case
 584                         try {
 585                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 586                         } catch ( DBError $e2 ) {
 587                                 // Rollback threw an exception too. Log it, but don't interrupt
 588                                 // our regularly scheduled exception handling.
 589                                 MWExceptionHandler::logException( $e2 );
 590                         }
 591                 }
 592
 593                 // Allow extra cleanup and logging
 594                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 595
 596                 // Log it
 597                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 598                         MWExceptionHandler::logException( $e );
 599                 }
 600
 601                 // Handle any kind of exception by outputting properly formatted error message.
 602                 // If this fails, an unhandled exception should be thrown so that global error
 603                 // handler will process and log it.
 604
 605                 $errCodes = $this->substituteResultWithError( $e );
 606
 607                 // Error results should not be cached
 608                 $this->setCacheMode( 'private' );
 609
 610                 $response = $this->getRequest()->response();
 611                 $headerStr = 'MediaWiki-API-Error: ' . join( ', ', $errCodes );
 612                 $response->header( $headerStr );
 613
 614                 // Reset and print just the error message
 615                 ob_clean();
 616
 617                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 618                 $this->createErrorPrinter();
 619
 620                 $failed = false;
 621                 try {
 622                         $this->printResult( $e->getCode() );
 623                 } catch ( ApiUsageException $ex ) {
 624                         // The error printer itself is failing. Try suppressing its request
 625                         // parameters and redo.
 626                         $failed = true;
 627                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 628                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 629                                 try {
 630                                         $this->mPrinter->addWarning( $error );
 631                                 } catch ( Exception $ex2 ) {
 632                                         // WTF?
 633                                         $this->addWarning( $error );
 634                                 }
 635                         }
 636                 } catch ( UsageException $ex ) {
 637                         // The error printer itself is failing. Try suppressing its request
 638                         // parameters and redo.
 639                         $failed = true;
 640                         $this->addWarning(
 641                                 [ 'apiwarn-errorprinterfailed-ex', $ex->getMessage() ], 'errorprinterfailed'
 642                         );
 643                 }
 644                 if ( $failed ) {
 645                         $this->mPrinter = null;
 646                         $this->createErrorPrinter();
 647                         $this->mPrinter->forceDefaultParams();
 648                         if ( $e->getCode() ) {
 649                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 650                         }
 651                         $this->printResult( $e->getCode() );
 652                 }
 653         }
 654
 655         /**
 656          * Handle an exception from the ApiBeforeMain hook.
 657          *
 658          * This tries to print the exception as an API response, to be more
 659          * friendly to clients. If it fails, it will rethrow the exception.
 660          *
 661          * @since 1.23
 662          * @param Exception $e
 663          * @throws Exception
 664          */
 665         public static function handleApiBeforeMainException( Exception $e ) {
 666                 ob_start();
 667
 668                 try {
 669                         $main = new self( RequestContext::getMain(), false );
 670                         $main->handleException( $e );
 671                         $main->logRequest( 0, $e );
 672                 } catch ( Exception $e2 ) {
 673                         // Nope, even that didn't work. Punt.
 674                         throw $e;
 675                 }
 676
 677                 // Reset cache headers
 678                 $main->sendCacheHeaders( true );
 679
 680                 ob_end_flush();
 681         }
 682
 683         /**
 684          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 685          *
 686          * If no origin parameter is present, nothing happens.
 687          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 688          * is set and false is returned.
 689          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 690          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 691          * headers are set.
 692          * https://www.w3.org/TR/cors/#resource-requests
 693          * https://www.w3.org/TR/cors/#resource-preflight-requests
 694          *
 695          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 696          */
 697         protected function handleCORS() {
 698                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 699                 if ( $originParam === null ) {
 700                         // No origin parameter, nothing to do
 701                         return true;
 702                 }
 703
 704                 $request = $this->getRequest();
 705                 $response = $request->response();
 706
 707                 $matchedOrigin = false;
 708                 $allowTiming = false;
 709                 $varyOrigin = true;
 710
 711                 if ( $originParam === '*' ) {
 712                         // Request for anonymous CORS
 713                         // Technically we should check for the presence of an Origin header
 714                         // and not process it as CORS if it's not set, but that would
 715                         // require us to vary on Origin for all 'origin=*' requests which
 716                         // we don't want to do.
 717                         $matchedOrigin = true;
 718                         $allowOrigin = '*';
 719                         $allowCredentials = 'false';
 720                         $varyOrigin = false; // No need to vary
 721                 } else {
 722                         // Non-anonymous CORS, check we allow the domain
 723
 724                         // Origin: header is a space-separated list of origins, check all of them
 725                         $originHeader = $request->getHeader( 'Origin' );
 726                         if ( $originHeader === false ) {
 727                                 $origins = [];
 728                         } else {
 729                                 $originHeader = trim( $originHeader );
 730                                 $origins = preg_split( '/\s+/', $originHeader );
 731                         }
 732
 733                         if ( !in_array( $originParam, $origins ) ) {
 734                                 // origin parameter set but incorrect
 735                                 // Send a 403 response
 736                                 $response->statusHeader( 403 );
 737                                 $response->header( 'Cache-Control: no-cache' );
 738                                 echo "'origin' parameter does not match Origin header\n";
 739
 740                                 return false;
 741                         }
 742
 743                         $config = $this->getConfig();
 744                         $matchedOrigin = count( $origins ) === 1 && self::matchOrigin(
 745                                 $originParam,
 746                                 $config->get( 'CrossSiteAJAXdomains' ),
 747                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 748                         );
 749
 750                         $allowOrigin = $originHeader;
 751                         $allowCredentials = 'true';
 752                         $allowTiming = $originHeader;
 753                 }
 754
 755                 if ( $matchedOrigin ) {
 756                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 757                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 758                         if ( $preflight ) {
 759                                 // This is a CORS preflight request
 760                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 761                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 762                                         $response->header( 'MediaWiki-CORS-Rejection: Unsupported method requested in preflight' );
 763                                         return true;
 764                                 }
 765                                 // We allow the actual request to send the following headers
 766                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 767                                 if ( $requestedHeaders !== false ) {
 768                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 769                                                 $response->header( 'MediaWiki-CORS-Rejection: Unsupported header requested in preflight' );
 770                                                 return true;
 771                                         }
 772                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 773                                 }
 774
 775                                 // We only allow the actual request to be GET or POST
 776                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 777                         } elseif ( $request->getMethod() !== 'POST' && $request->getMethod() !== 'GET' ) {
 778                                 // Unsupported non-preflight method, don't handle it as CORS
 779                                 $response->header(
 780                                         'MediaWiki-CORS-Rejection: Unsupported method for simple request or actual request'
 781                                 );
 782                                 return true;
 783                         }
 784
 785                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 786                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 787                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 788                         if ( $allowTiming !== false ) {
 789                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 790                         }
 791
 792                         if ( !$preflight ) {
 793                                 $response->header(
 794                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag, '
 795                                         . 'MediaWiki-Login-Suppressed'
 796                                 );
 797                         }
 798                 } else {
 799                         $response->header( 'MediaWiki-CORS-Rejection: Origin mismatch' );
 800                 }
 801
 802                 if ( $varyOrigin ) {
 803                         $this->getOutput()->addVaryHeader( 'Origin' );
 804                 }
 805
 806                 return true;
 807         }
 808
 809         /**
 810          * Attempt to match an Origin header against a set of rules and a set of exceptions
 811          * @param string $value Origin header
 812          * @param array $rules Set of wildcard rules
 813          * @param array $exceptions Set of wildcard rules
 814          * @return bool True if $value matches a rule in $rules and doesn't match
 815          *    any rules in $exceptions, false otherwise
 816          */
 817         protected static function matchOrigin( $value, $rules, $exceptions ) {
 818                 foreach ( $rules as $rule ) {
 819                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 820                                 // Rule matches, check exceptions
 821                                 foreach ( $exceptions as $exc ) {
 822                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 823                                                 return false;
 824                                         }
 825                                 }
 826
 827                                 return true;
 828                         }
 829                 }
 830
 831                 return false;
 832         }
 833
 834         /**
 835          * Attempt to validate the value of Access-Control-Request-Headers against a list
 836          * of headers that we allow the follow up request to send.
 837          *
 838          * @param string $requestedHeaders Comma seperated list of HTTP headers
 839          * @return bool True if all requested headers are in the list of allowed headers
 840          */
 841         protected static function matchRequestedHeaders( $requestedHeaders ) {
 842                 if ( trim( $requestedHeaders ) === '' ) {
 843                         return true;
 844                 }
 845                 $requestedHeaders = explode( ',', $requestedHeaders );
 846                 $allowedAuthorHeaders = array_flip( [
 847                         /* simple headers (see spec) */
 848                         'accept',
 849                         'accept-language',
 850                         'content-language',
 851                         'content-type',
 852                         /* non-authorable headers in XHR, which are however requested by some UAs */
 853                         'accept-encoding',
 854                         'dnt',
 855                         'origin',
 856                         /* MediaWiki whitelist */
 857                         'api-user-agent',
 858                 ] );
 859                 foreach ( $requestedHeaders as $rHeader ) {
 860                         $rHeader = strtolower( trim( $rHeader ) );
 861                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 862                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 863                                 return false;
 864                         }
 865                 }
 866                 return true;
 867         }
 868
 869         /**
 870          * Helper function to convert wildcard string into a regex
 871          * '*' => '.*?'
 872          * '?' => '.'
 873          *
 874          * @param string $wildcard String with wildcards
 875          * @return string Regular expression
 876          */
 877         protected static function wildcardToRegex( $wildcard ) {
 878                 $wildcard = preg_quote( $wildcard, '/' );
 879                 $wildcard = str_replace(
 880                         [ '\*', '\?' ],
 881                         [ '.*?', '.' ],
 882                         $wildcard
 883                 );
 884
 885                 return "/^https?:\/\/$wildcard$/";
 886         }
 887
 888         /**
 889          * Send caching headers
 890          * @param bool $isError Whether an error response is being output
 891          * @since 1.26 added $isError parameter
 892          */
 893         protected function sendCacheHeaders( $isError ) {
 894                 $response = $this->getRequest()->response();
 895                 $out = $this->getOutput();
 896
 897                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 898
 899                 $config = $this->getConfig();
 900
 901                 if ( $config->get( 'VaryOnXFP' ) ) {
 902                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 903                 }
 904
 905                 if ( !$isError && $this->mModule &&
 906                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 907                 ) {
 908                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 909                         if ( $etag !== null ) {
 910                                 $response->header( "ETag: $etag" );
 911                         }
 912                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 913                         if ( $lastMod !== null ) {
 914                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 915                         }
 916                 }
 917
 918                 // The logic should be:
 919                 // $this->mCacheControl['max-age'] is set?
 920                 //    Use it, the module knows better than our guess.
 921                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 922                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 923                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 924                 $maxage = 0;
 925                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 926                         $maxage = $this->mCacheControl['max-age'];
 927                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 928                         $this->mCacheMode !== 'private'
 929                 ) {
 930                         $maxage = $this->getParameter( 'maxage' );
 931                 }
 932                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 933
 934                 if ( $this->mCacheMode == 'private' ) {
 935                         $response->header( "Cache-Control: $privateCache" );
 936                         return;
 937                 }
 938
 939                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 940                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 941                         $out->addVaryHeader( 'Cookie' );
 942                         $response->header( $out->getVaryHeader() );
 943                         if ( $useKeyHeader ) {
 944                                 $response->header( $out->getKeyHeader() );
 945                                 if ( $out->haveCacheVaryCookies() ) {
 946                                         // Logged in, mark this request private
 947                                         $response->header( "Cache-Control: $privateCache" );
 948                                         return;
 949                                 }
 950                                 // Logged out, send normal public headers below
 951                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 952                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 953                                 // Mark request private
 954                                 $response->header( "Cache-Control: $privateCache" );
 955
 956                                 return;
 957                         } // else no Key and anonymous, send public headers below
 958                 }
 959
 960                 // Send public headers
 961                 $response->header( $out->getVaryHeader() );
 962                 if ( $useKeyHeader ) {
 963                         $response->header( $out->getKeyHeader() );
 964                 }
 965
 966                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 967                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 968                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 969                 }
 970                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 971                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 972                 }
 973
 974                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 975                         // Public cache not requested
 976                         // Sending a Vary header in this case is harmless, and protects us
 977                         // against conditional calls of setCacheMaxAge().
 978                         $response->header( "Cache-Control: $privateCache" );
 979
 980                         return;
 981                 }
 982
 983                 $this->mCacheControl['public'] = true;
 984
 985                 // Send an Expires header
 986                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 987                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 988                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 989
 990                 // Construct the Cache-Control header
 991                 $ccHeader = '';
 992                 $separator = '';
 993                 foreach ( $this->mCacheControl as $name => $value ) {
 994                         if ( is_bool( $value ) ) {
 995                                 if ( $value ) {
 996                                         $ccHeader .= $separator . $name;
 997                                         $separator = ', ';
 998                                 }
 999                         } else {
1000                                 $ccHeader .= $separator . "$name=$value";
1001                                 $separator = ', ';
1002                         }
1003                 }
1004
1005                 $response->header( "Cache-Control: $ccHeader" );
1006         }
1007
1008         /**
1009          * Create the printer for error output
1010          */
1011         private function createErrorPrinter() {
1012                 if ( !isset( $this->mPrinter ) ) {
1013                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
1014                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
1015                                 $value = self::API_DEFAULT_FORMAT;
1016                         }
1017                         $this->mPrinter = $this->createPrinterByName( $value );
1018                 }
1019
1020                 // Printer may not be able to handle errors. This is particularly
1021                 // likely if the module returns something for getCustomPrinter().
1022                 if ( !$this->mPrinter->canPrintErrors() ) {
1023                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1024                 }
1025         }
1026
1027         /**
1028          * Create an error message for the given exception.
1029          *
1030          * If an ApiUsageException, errors/warnings will be extracted from the
1031          * embedded StatusValue.
1032          *
1033          * If a base UsageException, the getMessageArray() method will be used to
1034          * extract the code and English message for a single error (no warnings).
1035          *
1036          * Any other exception will be returned with a generic code and wrapper
1037          * text around the exception's (presumably English) message as a single
1038          * error (no warnings).
1039          *
1040          * @param Exception $e
1041          * @param string $type 'error' or 'warning'
1042          * @return ApiMessage[]
1043          * @since 1.27
1044          */
1045         protected function errorMessagesFromException( $e, $type = 'error' ) {
1046                 $messages = [];
1047                 if ( $e instanceof ApiUsageException ) {
1048                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1049                                 $messages[] = ApiMessage::create( $error );
1050                         }
1051                 } elseif ( $type !== 'error' ) {
1052                         // None of the rest have any messages for non-error types
1053                 } elseif ( $e instanceof UsageException ) {
1054                         // User entered incorrect parameters - generate error response
1055                         $data = $e->getMessageArray();
1056                         $code = $data['code'];
1057                         $info = $data['info'];
1058                         unset( $data['code'], $data['info'] );
1059                         $messages[] = new ApiRawMessage( [ '$1', $info ], $code, $data );
1060                 } else {
1061                         // Something is seriously wrong
1062                         $config = $this->getConfig();
1063                         $class = preg_replace( '#^Wikimedia\\\Rdbms\\\#', '', get_class( $e ) );
1064                         $code = 'internal_api_error_' . $class;
1065                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
1066                                 $params = [ 'apierror-databaseerror', WebRequest::getRequestId() ];
1067                         } else {
1068                                 $params = [
1069                                         'apierror-exceptioncaught',
1070                                         WebRequest::getRequestId(),
1071                                         $e instanceof ILocalizedException
1072                                                 ? $e->getMessageObject()
1073                                                 : wfEscapeWikiText( $e->getMessage() )
1074                                 ];
1075                         }
1076                         $messages[] = ApiMessage::create( $params, $code );
1077                 }
1078                 return $messages;
1079         }
1080
1081         /**
1082          * Replace the result data with the information about an exception.
1083          * @param Exception $e
1084          * @return string[] Error codes
1085          */
1086         protected function substituteResultWithError( $e ) {
1087                 $result = $this->getResult();
1088                 $formatter = $this->getErrorFormatter();
1089                 $config = $this->getConfig();
1090                 $errorCodes = [];
1091
1092                 // Remember existing warnings and errors across the reset
1093                 $errors = $result->getResultData( [ 'errors' ] );
1094                 $warnings = $result->getResultData( [ 'warnings' ] );
1095                 $result->reset();
1096                 if ( $warnings !== null ) {
1097                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1098                 }
1099                 if ( $errors !== null ) {
1100                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1101
1102                         // Collect the copied error codes for the return value
1103                         foreach ( $errors as $error ) {
1104                                 if ( isset( $error['code'] ) ) {
1105                                         $errorCodes[$error['code']] = true;
1106                                 }
1107                         }
1108                 }
1109
1110                 // Add errors from the exception
1111                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1112                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1113                         $errorCodes[$msg->getApiCode()] = true;
1114                         $formatter->addError( $modulePath, $msg );
1115                 }
1116                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1117                         $formatter->addWarning( $modulePath, $msg );
1118                 }
1119
1120                 // Add additional data. Path depends on whether we're in BC mode or not.
1121                 // Data depends on the type of exception.
1122                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1123                         $path = [ 'error' ];
1124                 } else {
1125                         $path = null;
1126                 }
1127                 if ( $e instanceof ApiUsageException || $e instanceof UsageException ) {
1128                         $link = wfExpandUrl( wfScript( 'api' ) );
1129                         $result->addContentValue(
1130                                 $path,
1131                                 'docref',
1132                                 trim(
1133                                         $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1134                                         . ' '
1135                                         . $this->msg( 'api-usage-mailinglist-ref' )->inLanguage( $formatter->getLanguage() )->text()
1136                                 )
1137                         );
1138                 } else {
1139                         if ( $config->get( 'ShowExceptionDetails' ) &&
1140                                 ( !$e instanceof DBError || $config->get( 'ShowDBErrorBacktrace' ) )
1141                         ) {
1142                                 $result->addContentValue(
1143                                         $path,
1144                                         'trace',
1145                                         $this->msg( 'api-exception-trace',
1146                                                 get_class( $e ),
1147                                                 $e->getFile(),
1148                                                 $e->getLine(),
1149                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1150                                         )->inLanguage( $formatter->getLanguage() )->text()
1151                                 );
1152                         }
1153                 }
1154
1155                 // Add the id and such
1156                 $this->addRequestedFields( [ 'servedby' ] );
1157
1158                 return array_keys( $errorCodes );
1159         }
1160
1161         /**
1162          * Add requested fields to the result
1163          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1164          *  - servedby
1165          */
1166         protected function addRequestedFields( $force = [] ) {
1167                 $result = $this->getResult();
1168
1169                 $requestid = $this->getParameter( 'requestid' );
1170                 if ( $requestid !== null ) {
1171                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1172                 }
1173
1174                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1175                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1176                 ) ) {
1177                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1178                 }
1179
1180                 if ( $this->getParameter( 'curtimestamp' ) ) {
1181                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1182                                 ApiResult::NO_SIZE_CHECK );
1183                 }
1184
1185                 if ( $this->getParameter( 'responselanginfo' ) ) {
1186                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1187                                 ApiResult::NO_SIZE_CHECK );
1188                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1189                                 ApiResult::NO_SIZE_CHECK );
1190                 }
1191         }
1192
1193         /**
1194          * Set up for the execution.
1195          * @return array
1196          */
1197         protected function setupExecuteAction() {
1198                 $this->addRequestedFields();
1199
1200                 $params = $this->extractRequestParams();
1201                 $this->mAction = $params['action'];
1202
1203                 return $params;
1204         }
1205
1206         /**
1207          * Set up the module for response
1208          * @return ApiBase The module that will handle this action
1209          * @throws MWException
1210          * @throws ApiUsageException
1211          */
1212         protected function setupModule() {
1213                 // Instantiate the module requested by the user
1214                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1215                 if ( $module === null ) {
1216                         $this->dieWithError(
1217                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1218                         );
1219                 }
1220                 $moduleParams = $module->extractRequestParams();
1221
1222                 // Check token, if necessary
1223                 if ( $module->needsToken() === true ) {
1224                         throw new MWException(
1225                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1226                                 'See documentation for ApiBase::needsToken for details.'
1227                         );
1228                 }
1229                 if ( $module->needsToken() ) {
1230                         if ( !$module->mustBePosted() ) {
1231                                 throw new MWException(
1232                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1233                                 );
1234                         }
1235
1236                         if ( !isset( $moduleParams['token'] ) ) {
1237                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1238                         }
1239
1240                         $module->requirePostedParameters( [ 'token' ] );
1241
1242                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1243                                 $module->dieWithError( 'apierror-badtoken' );
1244                         }
1245                 }
1246
1247                 return $module;
1248         }
1249
1250         /**
1251          * @return array
1252          */
1253         private function getMaxLag() {
1254                 $dbLag = MediaWikiServices::getInstance()->getDBLoadBalancer()->getMaxLag();
1255                 $lagInfo = [
1256                         'host' => $dbLag[0],
1257                         'lag' => $dbLag[1],
1258                         'type' => 'db'
1259                 ];
1260
1261                 $jobQueueLagFactor = $this->getConfig()->get( 'JobQueueIncludeInMaxLagFactor' );
1262                 if ( $jobQueueLagFactor ) {
1263                         // Turn total number of jobs into seconds by using the configured value
1264                         $totalJobs = array_sum( JobQueueGroup::singleton()->getQueueSizes() );
1265                         $jobQueueLag = $totalJobs / (float)$jobQueueLagFactor;
1266                         if ( $jobQueueLag > $lagInfo['lag'] ) {
1267                                 $lagInfo = [
1268                                         'host' => wfHostname(), // XXX: Is there a better value that could be used?
1269                                         'lag' => $jobQueueLag,
1270                                         'type' => 'jobqueue',
1271                                         'jobs' => $totalJobs,
1272                                 ];
1273                         }
1274                 }
1275
1276                 return $lagInfo;
1277         }
1278
1279         /**
1280          * Check the max lag if necessary
1281          * @param ApiBase $module Api module being used
1282          * @param array $params Array an array containing the request parameters.
1283          * @return bool True on success, false should exit immediately
1284          */
1285         protected function checkMaxLag( $module, $params ) {
1286                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1287                         $maxLag = $params['maxlag'];
1288                         $lagInfo = $this->getMaxLag();
1289                         if ( $lagInfo['lag'] > $maxLag ) {
1290                                 $response = $this->getRequest()->response();
1291
1292                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1293                                 $response->header( 'X-Database-Lag: ' . intval( $lagInfo['lag'] ) );
1294
1295                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1296                                         $this->dieWithError(
1297                                                 [ 'apierror-maxlag', $lagInfo['lag'], $lagInfo['host'] ],
1298                                                 'maxlag',
1299                                                 $lagInfo
1300                                         );
1301                                 }
1302
1303                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lagInfo['lag'] ], 'maxlag', $lagInfo );
1304                         }
1305                 }
1306
1307                 return true;
1308         }
1309
1310         /**
1311          * Check selected RFC 7232 precondition headers
1312          *
1313          * RFC 7232 envisions a particular model where you send your request to "a
1314          * resource", and for write requests that you can read "the resource" by
1315          * changing the method to GET. When the API receives a GET request, it
1316          * works out even though "the resource" from RFC 7232's perspective might
1317          * be many resources from MediaWiki's perspective. But it totally fails for
1318          * a POST, since what HTTP sees as "the resource" is probably just
1319          * "/api.php" with all the interesting bits in the body.
1320          *
1321          * Therefore, we only support RFC 7232 precondition headers for GET (and
1322          * HEAD). That means we don't need to bother with If-Match and
1323          * If-Unmodified-Since since they only apply to modification requests.
1324          *
1325          * And since we don't support Range, If-Range is ignored too.
1326          *
1327          * @since 1.26
1328          * @param ApiBase $module Api module being used
1329          * @return bool True on success, false should exit immediately
1330          */
1331         protected function checkConditionalRequestHeaders( $module ) {
1332                 if ( $this->mInternalMode ) {
1333                         // No headers to check in internal mode
1334                         return true;
1335                 }
1336
1337                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1338                         // Don't check POSTs
1339                         return true;
1340                 }
1341
1342                 $return304 = false;
1343
1344                 $ifNoneMatch = array_diff(
1345                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1346                         [ '' ]
1347                 );
1348                 if ( $ifNoneMatch ) {
1349                         if ( $ifNoneMatch === [ '*' ] ) {
1350                                 // API responses always "exist"
1351                                 $etag = '*';
1352                         } else {
1353                                 $etag = $module->getConditionalRequestData( 'etag' );
1354                         }
1355                 }
1356                 if ( $ifNoneMatch && $etag !== null ) {
1357                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1358                         $match = array_map( function ( $s ) {
1359                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1360                         }, $ifNoneMatch );
1361                         $return304 = in_array( $test, $match, true );
1362                 } else {
1363                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1364
1365                         // Some old browsers sends sizes after the date, like this:
1366                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1367                         // Ignore that.
1368                         $i = strpos( $value, ';' );
1369                         if ( $i !== false ) {
1370                                 $value = trim( substr( $value, 0, $i ) );
1371                         }
1372
1373                         if ( $value !== '' ) {
1374                                 try {
1375                                         $ts = new MWTimestamp( $value );
1376                                         if (
1377                                                 // RFC 7231 IMF-fixdate
1378                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1379                                                 // RFC 850
1380                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1381                                                 // asctime (with and without space-padded day)
1382                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1383                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1384                                         ) {
1385                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1386                                                 if ( $lastMod !== null ) {
1387                                                         // Mix in some MediaWiki modification times
1388                                                         $modifiedTimes = [
1389                                                                 'page' => $lastMod,
1390                                                                 'user' => $this->getUser()->getTouched(),
1391                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1392                                                         ];
1393                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1394                                                                 // T46570: the core page itself may not change, but resources might
1395                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1396                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1397                                                                 );
1398                                                         }
1399                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1400                                                         $lastMod = max( $modifiedTimes );
1401                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1402                                                 }
1403                                         }
1404                                 } catch ( TimestampException $e ) {
1405                                         // Invalid timestamp, ignore it
1406                                 }
1407                         }
1408                 }
1409
1410                 if ( $return304 ) {
1411                         $this->getRequest()->response()->statusHeader( 304 );
1412
1413                         // Avoid outputting the compressed representation of a zero-length body
1414                         MediaWiki\suppressWarnings();
1415                         ini_set( 'zlib.output_compression', 0 );
1416                         MediaWiki\restoreWarnings();
1417                         wfClearOutputBuffers();
1418
1419                         return false;
1420                 }
1421
1422                 return true;
1423         }
1424
1425         /**
1426          * Check for sufficient permissions to execute
1427          * @param ApiBase $module An Api module
1428          */
1429         protected function checkExecutePermissions( $module ) {
1430                 $user = $this->getUser();
1431                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1432                         !$user->isAllowed( 'read' )
1433                 ) {
1434                         $this->dieWithError( 'apierror-readapidenied' );
1435                 }
1436
1437                 if ( $module->isWriteMode() ) {
1438                         if ( !$this->mEnableWrite ) {
1439                                 $this->dieWithError( 'apierror-noapiwrite' );
1440                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1441                                 $this->dieWithError( 'apierror-writeapidenied' );
1442                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1443                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1444                         }
1445
1446                         $this->checkReadOnly( $module );
1447                 }
1448
1449                 // Allow extensions to stop execution for arbitrary reasons.
1450                 $message = false;
1451                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1452                         $this->dieWithError( $message );
1453                 }
1454         }
1455
1456         /**
1457          * Check if the DB is read-only for this user
1458          * @param ApiBase $module An Api module
1459          */
1460         protected function checkReadOnly( $module ) {
1461                 if ( wfReadOnly() ) {
1462                         $this->dieReadOnly();
1463                 }
1464
1465                 if ( $module->isWriteMode()
1466                         && $this->getUser()->isBot()
1467                         && wfGetLB()->getServerCount() > 1
1468                 ) {
1469                         $this->checkBotReadOnly();
1470                 }
1471         }
1472
1473         /**
1474          * Check whether we are readonly for bots
1475          */
1476         private function checkBotReadOnly() {
1477                 // Figure out how many servers have passed the lag threshold
1478                 $numLagged = 0;
1479                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1480                 $laggedServers = [];
1481                 $loadBalancer = wfGetLB();
1482                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1483                         if ( $lag > $lagLimit ) {
1484                                 ++$numLagged;
1485                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1486                         }
1487                 }
1488
1489                 // If a majority of replica DBs are too lagged then disallow writes
1490                 $replicaCount = wfGetLB()->getServerCount() - 1;
1491                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1492                         $laggedServers = implode( ', ', $laggedServers );
1493                         wfDebugLog(
1494                                 'api-readonly',
1495                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1496                         );
1497
1498                         $this->dieWithError(
1499                                 'readonly_lag',
1500                                 'readonly',
1501                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1502                         );
1503                 }
1504         }
1505
1506         /**
1507          * Check asserts of the user's rights
1508          * @param array $params
1509          */
1510         protected function checkAsserts( $params ) {
1511                 if ( isset( $params['assert'] ) ) {
1512                         $user = $this->getUser();
1513                         switch ( $params['assert'] ) {
1514                                 case 'user':
1515                                         if ( $user->isAnon() ) {
1516                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1517                                         }
1518                                         break;
1519                                 case 'bot':
1520                                         if ( !$user->isAllowed( 'bot' ) ) {
1521                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1522                                         }
1523                                         break;
1524                         }
1525                 }
1526                 if ( isset( $params['assertuser'] ) ) {
1527                         $assertUser = User::newFromName( $params['assertuser'], false );
1528                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1529                                 $this->dieWithError(
1530                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1531                                 );
1532                         }
1533                 }
1534         }
1535
1536         /**
1537          * Check POST for external response and setup result printer
1538          * @param ApiBase $module An Api module
1539          * @param array $params An array with the request parameters
1540          */
1541         protected function setupExternalResponse( $module, $params ) {
1542                 $request = $this->getRequest();
1543                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1544                         // Module requires POST. GET request might still be allowed
1545                         // if $wgDebugApi is true, otherwise fail.
1546                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1547                 }
1548
1549                 // See if custom printer is used
1550                 $this->mPrinter = $module->getCustomPrinter();
1551                 if ( is_null( $this->mPrinter ) ) {
1552                         // Create an appropriate printer
1553                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1554                 }
1555
1556                 if ( $request->getProtocol() === 'http' && (
1557                         $request->getSession()->shouldForceHTTPS() ||
1558                         ( $this->getUser()->isLoggedIn() &&
1559                                 $this->getUser()->requiresHTTPS() )
1560                 ) ) {
1561                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1562                 }
1563         }
1564
1565         /**
1566          * Execute the actual module, without any error handling
1567          */
1568         protected function executeAction() {
1569                 $params = $this->setupExecuteAction();
1570                 $module = $this->setupModule();
1571                 $this->mModule = $module;
1572
1573                 if ( !$this->mInternalMode ) {
1574                         $this->setRequestExpectations( $module );
1575                 }
1576
1577                 $this->checkExecutePermissions( $module );
1578
1579                 if ( !$this->checkMaxLag( $module, $params ) ) {
1580                         return;
1581                 }
1582
1583                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1584                         return;
1585                 }
1586
1587                 if ( !$this->mInternalMode ) {
1588                         $this->setupExternalResponse( $module, $params );
1589                 }
1590
1591                 $this->checkAsserts( $params );
1592
1593                 // Execute
1594                 $module->execute();
1595                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1596
1597                 $this->reportUnusedParams();
1598
1599                 if ( !$this->mInternalMode ) {
1600                         // append Debug information
1601                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1602
1603                         // Print result data
1604                         $this->printResult();
1605                 }
1606         }
1607
1608         /**
1609          * Set database connection, query, and write expectations given this module request
1610          * @param ApiBase $module
1611          */
1612         protected function setRequestExpectations( ApiBase $module ) {
1613                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1614                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1615                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1616                 if ( $this->getRequest()->hasSafeMethod() ) {
1617                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1618                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1619                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1620                         $this->getRequest()->markAsSafeRequest();
1621                 } else {
1622                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1623                 }
1624         }
1625
1626         /**
1627          * Log the preceding request
1628          * @param float $time Time in seconds
1629          * @param Exception $e Exception caught while processing the request
1630          */
1631         protected function logRequest( $time, $e = null ) {
1632                 $request = $this->getRequest();
1633                 $logCtx = [
1634                         'ts' => time(),
1635                         'ip' => $request->getIP(),
1636                         'userAgent' => $this->getUserAgent(),
1637                         'wiki' => wfWikiID(),
1638                         'timeSpentBackend' => (int)round( $time * 1000 ),
1639                         'hadError' => $e !== null,
1640                         'errorCodes' => [],
1641                         'params' => [],
1642                 ];
1643
1644                 if ( $e ) {
1645                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1646                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1647                         }
1648                 }
1649
1650                 // Construct space separated message for 'api' log channel
1651                 $msg = "API {$request->getMethod()} " .
1652                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1653                         " {$logCtx['ip']} " .
1654                         "T={$logCtx['timeSpentBackend']}ms";
1655
1656                 $sensitive = array_flip( $this->getSensitiveParams() );
1657                 foreach ( $this->getParamsUsed() as $name ) {
1658                         $value = $request->getVal( $name );
1659                         if ( $value === null ) {
1660                                 continue;
1661                         }
1662
1663                         if ( isset( $sensitive[$name] ) ) {
1664                                 $value = '[redacted]';
1665                                 $encValue = '[redacted]';
1666                         } elseif ( strlen( $value ) > 256 ) {
1667                                 $value = substr( $value, 0, 256 );
1668                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1669                         } else {
1670                                 $encValue = $this->encodeRequestLogValue( $value );
1671                         }
1672
1673                         $logCtx['params'][$name] = $value;
1674                         $msg .= " {$name}={$encValue}";
1675                 }
1676
1677                 wfDebugLog( 'api', $msg, 'private' );
1678                 // ApiAction channel is for structured data consumers
1679                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1680         }
1681
1682         /**
1683          * Encode a value in a format suitable for a space-separated log line.
1684          * @param string $s
1685          * @return string
1686          */
1687         protected function encodeRequestLogValue( $s ) {
1688                 static $table;
1689                 if ( !$table ) {
1690                         $chars = ';@$!*(),/:';
1691                         $numChars = strlen( $chars );
1692                         for ( $i = 0; $i < $numChars; $i++ ) {
1693                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1694                         }
1695                 }
1696
1697                 return strtr( rawurlencode( $s ), $table );
1698         }
1699
1700         /**
1701          * Get the request parameters used in the course of the preceding execute() request
1702          * @return array
1703          */
1704         protected function getParamsUsed() {
1705                 return array_keys( $this->mParamsUsed );
1706         }
1707
1708         /**
1709          * Mark parameters as used
1710          * @param string|string[] $params
1711          */
1712         public function markParamsUsed( $params ) {
1713                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1714         }
1715
1716         /**
1717          * Get the request parameters that should be considered sensitive
1718          * @since 1.29
1719          * @return array
1720          */
1721         protected function getSensitiveParams() {
1722                 return array_keys( $this->mParamsSensitive );
1723         }
1724
1725         /**
1726          * Mark parameters as sensitive
1727          * @since 1.29
1728          * @param string|string[] $params
1729          */
1730         public function markParamsSensitive( $params ) {
1731                 $this->mParamsSensitive += array_fill_keys( (array)$params, true );
1732         }
1733
1734         /**
1735          * Get a request value, and register the fact that it was used, for logging.
1736          * @param string $name
1737          * @param mixed $default
1738          * @return mixed
1739          */
1740         public function getVal( $name, $default = null ) {
1741                 $this->mParamsUsed[$name] = true;
1742
1743                 $ret = $this->getRequest()->getVal( $name );
1744                 if ( $ret === null ) {
1745                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1746                                 // See T12262 for why we don't just implode( '|', ... ) the
1747                                 // array.
1748                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1749                         }
1750                         $ret = $default;
1751                 }
1752                 return $ret;
1753         }
1754
1755         /**
1756          * Get a boolean request value, and register the fact that the parameter
1757          * was used, for logging.
1758          * @param string $name
1759          * @return bool
1760          */
1761         public function getCheck( $name ) {
1762                 return $this->getVal( $name, null ) !== null;
1763         }
1764
1765         /**
1766          * Get a request upload, and register the fact that it was used, for logging.
1767          *
1768          * @since 1.21
1769          * @param string $name Parameter name
1770          * @return WebRequestUpload
1771          */
1772         public function getUpload( $name ) {
1773                 $this->mParamsUsed[$name] = true;
1774
1775                 return $this->getRequest()->getUpload( $name );
1776         }
1777
1778         /**
1779          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1780          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1781          */
1782         protected function reportUnusedParams() {
1783                 $paramsUsed = $this->getParamsUsed();
1784                 $allParams = $this->getRequest()->getValueNames();
1785
1786                 if ( !$this->mInternalMode ) {
1787                         // Printer has not yet executed; don't warn that its parameters are unused
1788                         $printerParams = $this->mPrinter->encodeParamName(
1789                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1790                         );
1791                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1792                 } else {
1793                         $unusedParams = array_diff( $allParams, $paramsUsed );
1794                 }
1795
1796                 if ( count( $unusedParams ) ) {
1797                         $this->addWarning( [
1798                                 'apierror-unrecognizedparams',
1799                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1800                                 count( $unusedParams )
1801                         ] );
1802                 }
1803         }
1804
1805         /**
1806          * Print results using the current printer
1807          *
1808          * @param int $httpCode HTTP status code, or 0 to not change
1809          */
1810         protected function printResult( $httpCode = 0 ) {
1811                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1812                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1813                 }
1814
1815                 $printer = $this->mPrinter;
1816                 $printer->initPrinter( false );
1817                 if ( $httpCode ) {
1818                         $printer->setHttpStatus( $httpCode );
1819                 }
1820                 $printer->execute();
1821                 $printer->closePrinter();
1822         }
1823
1824         /**
1825          * @return bool
1826          */
1827         public function isReadMode() {
1828                 return false;
1829         }
1830
1831         /**
1832          * See ApiBase for description.
1833          *
1834          * @return array
1835          */
1836         public function getAllowedParams() {
1837                 return [
1838                         'action' => [
1839                                 ApiBase::PARAM_DFLT => 'help',
1840                                 ApiBase::PARAM_TYPE => 'submodule',
1841                         ],
1842                         'format' => [
1843                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1844                                 ApiBase::PARAM_TYPE => 'submodule',
1845                         ],
1846                         'maxlag' => [
1847                                 ApiBase::PARAM_TYPE => 'integer'
1848                         ],
1849                         'smaxage' => [
1850                                 ApiBase::PARAM_TYPE => 'integer',
1851                                 ApiBase::PARAM_DFLT => 0
1852                         ],
1853                         'maxage' => [
1854                                 ApiBase::PARAM_TYPE => 'integer',
1855                                 ApiBase::PARAM_DFLT => 0
1856                         ],
1857                         'assert' => [
1858                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1859                         ],
1860                         'assertuser' => [
1861                                 ApiBase::PARAM_TYPE => 'user',
1862                         ],
1863                         'requestid' => null,
1864                         'servedby' => false,
1865                         'curtimestamp' => false,
1866                         'responselanginfo' => false,
1867                         'origin' => null,
1868                         'uselang' => [
1869                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1870                         ],
1871                         'errorformat' => [
1872                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1873                                 ApiBase::PARAM_DFLT => 'bc',
1874                         ],
1875                         'errorlang' => [
1876                                 ApiBase::PARAM_DFLT => 'uselang',
1877                         ],
1878                         'errorsuselocal' => [
1879                                 ApiBase::PARAM_DFLT => false,
1880                         ],
1881                 ];
1882         }
1883
1884         /** @see ApiBase::getExamplesMessages() */
1885         protected function getExamplesMessages() {
1886                 return [
1887                         'action=help'
1888                                 => 'apihelp-help-example-main',
1889                         'action=help&recursivesubmodules=1'
1890                                 => 'apihelp-help-example-recursive',
1891                 ];
1892         }
1893
1894         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1895                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1896                 // reindex the array to get 'permissions' in the right place.
1897                 $oldHelp = $help;
1898                 $help = [];
1899                 foreach ( $oldHelp as $k => $v ) {
1900                         if ( $k === 'submodules' ) {
1901                                 $help['permissions'] = '';
1902                         }
1903                         $help[$k] = $v;
1904                 }
1905                 $help['datatypes'] = '';
1906                 $help['credits'] = '';
1907
1908                 // Fill 'permissions'
1909                 $help['permissions'] .= Html::openElement( 'div',
1910                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1911                 $m = $this->msg( 'api-help-permissions' );
1912                 if ( !$m->isDisabled() ) {
1913                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1914                                 $m->numParams( count( self::$mRights ) )->parse()
1915                         );
1916                 }
1917                 $help['permissions'] .= Html::openElement( 'dl' );
1918                 foreach ( self::$mRights as $right => $rightMsg ) {
1919                         $help['permissions'] .= Html::element( 'dt', null, $right );
1920
1921                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1922                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1923
1924                         $groups = array_map( function ( $group ) {
1925                                 return $group == '*' ? 'all' : $group;
1926                         }, User::getGroupsWithPermission( $right ) );
1927
1928                         $help['permissions'] .= Html::rawElement( 'dd', null,
1929                                 $this->msg( 'api-help-permissions-granted-to' )
1930                                         ->numParams( count( $groups ) )
1931                                         ->params( Message::listParam( $groups ) )
1932                                         ->parse()
1933                         );
1934                 }
1935                 $help['permissions'] .= Html::closeElement( 'dl' );
1936                 $help['permissions'] .= Html::closeElement( 'div' );
1937
1938                 // Fill 'datatypes' and 'credits', if applicable
1939                 if ( empty( $options['nolead'] ) ) {
1940                         $level = $options['headerlevel'];
1941                         $tocnumber = &$options['tocnumber'];
1942
1943                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1944
1945                         // Add an additional span with sanitized ID
1946                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1947                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1948                                         $header;
1949                         }
1950                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1951                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1952                                 $header
1953                         );
1954                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1955                         if ( !isset( $tocData['main/datatypes'] ) ) {
1956                                 $tocnumber[$level]++;
1957                                 $tocData['main/datatypes'] = [
1958                                         'toclevel' => count( $tocnumber ),
1959                                         'level' => $level,
1960                                         'anchor' => 'main/datatypes',
1961                                         'line' => $header,
1962                                         'number' => implode( '.', $tocnumber ),
1963                                         'index' => false,
1964                                 ];
1965                         }
1966
1967                         // Add an additional span with sanitized ID
1968                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1969                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1970                                         $header;
1971                         }
1972                         $header = $this->msg( 'api-credits-header' )->parse();
1973                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1974                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1975                                 $header
1976                         );
1977                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1978                         if ( !isset( $tocData['main/credits'] ) ) {
1979                                 $tocnumber[$level]++;
1980                                 $tocData['main/credits'] = [
1981                                         'toclevel' => count( $tocnumber ),
1982                                         'level' => $level,
1983                                         'anchor' => 'main/credits',
1984                                         'line' => $header,
1985                                         'number' => implode( '.', $tocnumber ),
1986                                         'index' => false,
1987                                 ];
1988                         }
1989                 }
1990         }
1991
1992         private $mCanApiHighLimits = null;
1993
1994         /**
1995          * Check whether the current user is allowed to use high limits
1996          * @return bool
1997          */
1998         public function canApiHighLimits() {
1999                 if ( !isset( $this->mCanApiHighLimits ) ) {
2000                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
2001                 }
2002
2003                 return $this->mCanApiHighLimits;
2004         }
2005
2006         /**
2007          * Overrides to return this instance's module manager.
2008          * @return ApiModuleManager
2009          */
2010         public function getModuleManager() {
2011                 return $this->mModuleMgr;
2012         }
2013
2014         /**
2015          * Fetches the user agent used for this request
2016          *
2017          * The value will be the combination of the 'Api-User-Agent' header (if
2018          * any) and the standard User-Agent header (if any).
2019          *
2020          * @return string
2021          */
2022         public function getUserAgent() {
2023                 return trim(
2024                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
2025                         $this->getRequest()->getHeader( 'User-agent' )
2026                 );
2027         }
2028 }
2029
2030 /**
2031  * For really cool vim folding this needs to be at the end:
2032  * vim: foldmarker=@{,@} foldmethod=marker
2033  */