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