includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @defgroup API API
  26  */
  27
  28 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42         /**
  43          * When no format parameter is given, this format will be used
  44          */
  45         const API_DEFAULT_FORMAT = 'jsonfm';
  46
  47         /**
  48          * List of available modules: action name => module class
  49          */
  50         private static $Modules = [
  51                 'login' => 'ApiLogin',
  52                 'clientlogin' => 'ApiClientLogin',
  53                 'logout' => 'ApiLogout',
  54                 'createaccount' => 'ApiAMCreateAccount',
  55                 'linkaccount' => 'ApiLinkAccount',
  56                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  57                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  58                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  59                 'resetpassword' => 'ApiResetPassword',
  60                 'query' => 'ApiQuery',
  61                 'expandtemplates' => 'ApiExpandTemplates',
  62                 'parse' => 'ApiParse',
  63                 'stashedit' => 'ApiStashEdit',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedcontributions' => 'ApiFeedContributions',
  66                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  67                 'feedwatchlist' => 'ApiFeedWatchlist',
  68                 'help' => 'ApiHelp',
  69                 'paraminfo' => 'ApiParamInfo',
  70                 'rsd' => 'ApiRsd',
  71                 'compare' => 'ApiComparePages',
  72                 'tokens' => 'ApiTokens',
  73                 'checktoken' => 'ApiCheckToken',
  74                 'cspreport' => 'ApiCSPReport',
  75
  76                 // Write modules
  77                 'purge' => 'ApiPurge',
  78                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  79                 'rollback' => 'ApiRollback',
  80                 'delete' => 'ApiDelete',
  81                 'undelete' => 'ApiUndelete',
  82                 'protect' => 'ApiProtect',
  83                 'block' => 'ApiBlock',
  84                 'unblock' => 'ApiUnblock',
  85                 'move' => 'ApiMove',
  86                 'edit' => 'ApiEditPage',
  87                 'upload' => 'ApiUpload',
  88                 'filerevert' => 'ApiFileRevert',
  89                 'emailuser' => 'ApiEmailUser',
  90                 'watch' => 'ApiWatch',
  91                 'patrol' => 'ApiPatrol',
  92                 'import' => 'ApiImport',
  93                 'clearhasmsg' => 'ApiClearHasMsg',
  94                 'userrights' => 'ApiUserrights',
  95                 'options' => 'ApiOptions',
  96                 'imagerotate' => 'ApiImageRotate',
  97                 'revisiondelete' => 'ApiRevisionDelete',
  98                 'managetags' => 'ApiManageTags',
  99                 'tag' => 'ApiTag',
 100                 'mergehistory' => 'ApiMergeHistory',
 101         ];
 102
 103         /**
 104          * List of available formats: format name => format class
 105          */
 106         private static $Formats = [
 107                 'json' => 'ApiFormatJson',
 108                 'jsonfm' => 'ApiFormatJson',
 109                 'php' => 'ApiFormatPhp',
 110                 'phpfm' => 'ApiFormatPhp',
 111                 'xml' => 'ApiFormatXml',
 112                 'xmlfm' => 'ApiFormatXml',
 113                 'rawfm' => 'ApiFormatJson',
 114                 'none' => 'ApiFormatNone',
 115         ];
 116
 117         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 118         /**
 119          * List of user roles that are specifically relevant to the API.
 120          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 121          *                           'params' => array ( $someVarToSubst ) ),
 122          *                          );
 123          */
 124         private static $mRights = [
 125                 'writeapi' => [
 126                         'msg' => 'right-writeapi',
 127                         'params' => []
 128                 ],
 129                 'apihighlimits' => [
 130                         'msg' => 'api-help-right-apihighlimits',
 131                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 132                 ]
 133         ];
 134         // @codingStandardsIgnoreEnd
 135
 136         /**
 137          * @var ApiFormatBase
 138          */
 139         private $mPrinter;
 140
 141         private $mModuleMgr, $mResult, $mErrorFormatter;
 142         /** @var ApiContinuationManager|null */
 143         private $mContinuationManager;
 144         private $mAction;
 145         private $mEnableWrite;
 146         private $mInternalMode, $mSquidMaxage;
 147         /** @var ApiBase */
 148         private $mModule;
 149
 150         private $mCacheMode = 'private';
 151         private $mCacheControl = [];
 152         private $mParamsUsed = [];
 153
 154         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 155         private $lacksSameOriginSecurity = null;
 156
 157         /**
 158          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 159          *
 160          * @param IContextSource|WebRequest $context If this is an instance of
 161          *    FauxRequest, errors are thrown and no printing occurs
 162          * @param bool $enableWrite Should be set to true if the api may modify data
 163          */
 164         public function __construct( $context = null, $enableWrite = false ) {
 165                 if ( $context === null ) {
 166                         $context = RequestContext::getMain();
 167                 } elseif ( $context instanceof WebRequest ) {
 168                         // BC for pre-1.19
 169                         $request = $context;
 170                         $context = RequestContext::getMain();
 171                 }
 172                 // We set a derivative context so we can change stuff later
 173                 $this->setContext( new DerivativeContext( $context ) );
 174
 175                 if ( isset( $request ) ) {
 176                         $this->getContext()->setRequest( $request );
 177                 } else {
 178                         $request = $this->getRequest();
 179                 }
 180
 181                 $this->mInternalMode = ( $request instanceof FauxRequest );
 182
 183                 // Special handling for the main module: $parent === $this
 184                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 185
 186                 $config = $this->getConfig();
 187
 188                 if ( !$this->mInternalMode ) {
 189                         // Log if a request with a non-whitelisted Origin header is seen
 190                         // with session cookies.
 191                         $originHeader = $request->getHeader( 'Origin' );
 192                         if ( $originHeader === false ) {
 193                                 $origins = [];
 194                         } else {
 195                                 $originHeader = trim( $originHeader );
 196                                 $origins = preg_split( '/\s+/', $originHeader );
 197                         }
 198                         $sessionCookies = array_intersect(
 199                                 array_keys( $_COOKIE ),
 200                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 201                         );
 202                         if ( $origins && $sessionCookies && (
 203                                 count( $origins ) !== 1 || !self::matchOrigin(
 204                                         $origins[0],
 205                                         $config->get( 'CrossSiteAJAXdomains' ),
 206                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 207                                 )
 208                         ) ) {
 209                                 MediaWiki\Logger\LoggerFactory::getInstance( 'cors' )->warning(
 210                                         'Non-whitelisted CORS request with session cookies', [
 211                                                 'origin' => $originHeader,
 212                                                 'cookies' => $sessionCookies,
 213                                                 'ip' => $request->getIP(),
 214                                                 'userAgent' => $this->getUserAgent(),
 215                                                 'wiki' => wfWikiID(),
 216                                         ]
 217                                 );
 218                         }
 219
 220                         // If we're in a mode that breaks the same-origin policy, strip
 221                         // user credentials for security.
 222                         if ( $this->lacksSameOriginSecurity() ) {
 223                                 global $wgUser;
 224                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 225                                 $wgUser = new User();
 226                                 $this->getContext()->setUser( $wgUser );
 227                         }
 228                 }
 229
 230                 $uselang = $this->getParameter( 'uselang' );
 231                 if ( $uselang === 'user' ) {
 232                         // Assume the parent context is going to return the user language
 233                         // for uselang=user (see T85635).
 234                 } else {
 235                         if ( $uselang === 'content' ) {
 236                                 global $wgContLang;
 237                                 $uselang = $wgContLang->getCode();
 238                         }
 239                         $code = RequestContext::sanitizeLangCode( $uselang );
 240                         $this->getContext()->setLanguage( $code );
 241                         if ( !$this->mInternalMode ) {
 242                                 global $wgLang;
 243                                 $wgLang = $this->getContext()->getLanguage();
 244                                 RequestContext::getMain()->setLanguage( $wgLang );
 245                         }
 246                 }
 247
 248                 $this->mModuleMgr = new ApiModuleManager( $this );
 249                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 250                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 251                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 252                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 253
 254                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 255
 256                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 257                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 258                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 259                 $this->mResult->setMainForContinuation( $this );
 260                 $this->mContinuationManager = null;
 261                 $this->mEnableWrite = $enableWrite;
 262
 263                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 264                 $this->mCommit = false;
 265         }
 266
 267         /**
 268          * Return true if the API was started by other PHP code using FauxRequest
 269          * @return bool
 270          */
 271         public function isInternalMode() {
 272                 return $this->mInternalMode;
 273         }
 274
 275         /**
 276          * Get the ApiResult object associated with current request
 277          *
 278          * @return ApiResult
 279          */
 280         public function getResult() {
 281                 return $this->mResult;
 282         }
 283
 284         /**
 285          * Get the security flag for the current request
 286          * @return bool
 287          */
 288         public function lacksSameOriginSecurity() {
 289                 if ( $this->lacksSameOriginSecurity !== null ) {
 290                         return $this->lacksSameOriginSecurity;
 291                 }
 292
 293                 $request = $this->getRequest();
 294
 295                 // JSONP mode
 296                 if ( $request->getVal( 'callback' ) !== null ) {
 297                         $this->lacksSameOriginSecurity = true;
 298                         return true;
 299                 }
 300
 301                 // Header to be used from XMLHTTPRequest when the request might
 302                 // otherwise be used for XSS.
 303                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 304                         $this->lacksSameOriginSecurity = true;
 305                         return true;
 306                 }
 307
 308                 // Allow extensions to override.
 309                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 310                 return $this->lacksSameOriginSecurity;
 311         }
 312
 313         /**
 314          * Get the ApiErrorFormatter object associated with current request
 315          * @return ApiErrorFormatter
 316          */
 317         public function getErrorFormatter() {
 318                 return $this->mErrorFormatter;
 319         }
 320
 321         /**
 322          * Get the continuation manager
 323          * @return ApiContinuationManager|null
 324          */
 325         public function getContinuationManager() {
 326                 return $this->mContinuationManager;
 327         }
 328
 329         /**
 330          * Set the continuation manager
 331          * @param ApiContinuationManager|null
 332          */
 333         public function setContinuationManager( $manager ) {
 334                 if ( $manager !== null ) {
 335                         if ( !$manager instanceof ApiContinuationManager ) {
 336                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 337                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 338                                 );
 339                         }
 340                         if ( $this->mContinuationManager !== null ) {
 341                                 throw new UnexpectedValueException(
 342                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 343                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 344                                 );
 345                         }
 346                 }
 347                 $this->mContinuationManager = $manager;
 348         }
 349
 350         /**
 351          * Get the API module object. Only works after executeAction()
 352          *
 353          * @return ApiBase
 354          */
 355         public function getModule() {
 356                 return $this->mModule;
 357         }
 358
 359         /**
 360          * Get the result formatter object. Only works after setupExecuteAction()
 361          *
 362          * @return ApiFormatBase
 363          */
 364         public function getPrinter() {
 365                 return $this->mPrinter;
 366         }
 367
 368         /**
 369          * Set how long the response should be cached.
 370          *
 371          * @param int $maxage
 372          */
 373         public function setCacheMaxAge( $maxage ) {
 374                 $this->setCacheControl( [
 375                         'max-age' => $maxage,
 376                         's-maxage' => $maxage
 377                 ] );
 378         }
 379
 380         /**
 381          * Set the type of caching headers which will be sent.
 382          *
 383          * @param string $mode One of:
 384          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 385          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 386          *         not provided by any of these means, the object will be private.
 387          *    - 'private':    Cache this object only in private client-side caches.
 388          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 389          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 390          *         set consistently for a given URL, it cannot be set differently depending on
 391          *         things like the contents of the database, or whether the user is logged in.
 392          *
 393          *  If the wiki does not allow anonymous users to read it, the mode set here
 394          *  will be ignored, and private caching headers will always be sent. In other words,
 395          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 396          *  view.
 397          *
 398          *  For user-dependent data, the private mode should generally be used. The
 399          *  anon-public-user-private mode should only be used where there is a particularly
 400          *  good performance reason for caching the anonymous response, but where the
 401          *  response to logged-in users may differ, or may contain private data.
 402          *
 403          *  If this function is never called, then the default will be the private mode.
 404          */
 405         public function setCacheMode( $mode ) {
 406                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 407                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 408
 409                         // Ignore for forwards-compatibility
 410                         return;
 411                 }
 412
 413                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 414                         // Private wiki, only private headers
 415                         if ( $mode !== 'private' ) {
 416                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 417
 418                                 return;
 419                         }
 420                 }
 421
 422                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 423                         // User language is used for i18n, so we don't want to publicly
 424                         // cache. Anons are ok, because if they have non-default language
 425                         // then there's an appropriate Vary header set by whatever set
 426                         // their non-default language.
 427                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 428                                 "'anon-public-user-private' due to uselang=user\n" );
 429                         $mode = 'anon-public-user-private';
 430                 }
 431
 432                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 433                 $this->mCacheMode = $mode;
 434         }
 435
 436         /**
 437          * Set directives (key/value pairs) for the Cache-Control header.
 438          * Boolean values will be formatted as such, by including or omitting
 439          * without an equals sign.
 440          *
 441          * Cache control values set here will only be used if the cache mode is not
 442          * private, see setCacheMode().
 443          *
 444          * @param array $directives
 445          */
 446         public function setCacheControl( $directives ) {
 447                 $this->mCacheControl = $directives + $this->mCacheControl;
 448         }
 449
 450         /**
 451          * Create an instance of an output formatter by its name
 452          *
 453          * @param string $format
 454          *
 455          * @return ApiFormatBase
 456          */
 457         public function createPrinterByName( $format ) {
 458                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 459                 if ( $printer === null ) {
 460                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 461                 }
 462
 463                 return $printer;
 464         }
 465
 466         /**
 467          * Execute api request. Any errors will be handled if the API was called by the remote client.
 468          */
 469         public function execute() {
 470                 if ( $this->mInternalMode ) {
 471                         $this->executeAction();
 472                 } else {
 473                         $this->executeActionWithErrorHandling();
 474                 }
 475         }
 476
 477         /**
 478          * Execute an action, and in case of an error, erase whatever partial results
 479          * have been accumulated, and replace it with an error message and a help screen.
 480          */
 481         protected function executeActionWithErrorHandling() {
 482                 // Verify the CORS header before executing the action
 483                 if ( !$this->handleCORS() ) {
 484                         // handleCORS() has sent a 403, abort
 485                         return;
 486                 }
 487
 488                 // Exit here if the request method was OPTIONS
 489                 // (assume there will be a followup GET or POST)
 490                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 491                         return;
 492                 }
 493
 494                 // In case an error occurs during data output,
 495                 // clear the output buffer and print just the error information
 496                 $obLevel = ob_get_level();
 497                 ob_start();
 498
 499                 $t = microtime( true );
 500                 $isError = false;
 501                 try {
 502                         $this->executeAction();
 503                         $runTime = microtime( true ) - $t;
 504                         $this->logRequest( $runTime );
 505                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 506                                 $this->getStats()->timing(
 507                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 508                                 );
 509                         }
 510                 } catch ( Exception $e ) {
 511                         $this->handleException( $e );
 512                         $this->logRequest( microtime( true ) - $t, $e );
 513                         $isError = true;
 514                 }
 515
 516                 // Commit DBs and send any related cookies and headers
 517                 MediaWiki::preOutputCommit( $this->getContext() );
 518
 519                 // Send cache headers after any code which might generate an error, to
 520                 // avoid sending public cache headers for errors.
 521                 $this->sendCacheHeaders( $isError );
 522
 523                 // Executing the action might have already messed with the output
 524                 // buffers.
 525                 while ( ob_get_level() > $obLevel ) {
 526                         ob_end_flush();
 527                 }
 528         }
 529
 530         /**
 531          * Handle an exception as an API response
 532          *
 533          * @since 1.23
 534          * @param Exception $e
 535          */
 536         protected function handleException( Exception $e ) {
 537                 // Bug 63145: Rollback any open database transactions
 538                 if ( !( $e instanceof UsageException ) ) {
 539                         // UsageExceptions are intentional, so don't rollback if that's the case
 540                         try {
 541                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 542                         } catch ( DBError $e2 ) {
 543                                 // Rollback threw an exception too. Log it, but don't interrupt
 544                                 // our regularly scheduled exception handling.
 545                                 MWExceptionHandler::logException( $e2 );
 546                         }
 547                 }
 548
 549                 // Allow extra cleanup and logging
 550                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 551
 552                 // Log it
 553                 if ( !( $e instanceof UsageException ) ) {
 554                         MWExceptionHandler::logException( $e );
 555                 }
 556
 557                 // Handle any kind of exception by outputting properly formatted error message.
 558                 // If this fails, an unhandled exception should be thrown so that global error
 559                 // handler will process and log it.
 560
 561                 $errCode = $this->substituteResultWithError( $e );
 562
 563                 // Error results should not be cached
 564                 $this->setCacheMode( 'private' );
 565
 566                 $response = $this->getRequest()->response();
 567                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 568                 if ( $e->getCode() === 0 ) {
 569                         $response->header( $headerStr );
 570                 } else {
 571                         $response->header( $headerStr, true, $e->getCode() );
 572                 }
 573
 574                 // Reset and print just the error message
 575                 ob_clean();
 576
 577                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 578                 $this->createErrorPrinter();
 579
 580                 try {
 581                         $this->printResult( true );
 582                 } catch ( UsageException $ex ) {
 583                         // The error printer itself is failing. Try suppressing its request
 584                         // parameters and redo.
 585                         $this->setWarning(
 586                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 587                         );
 588                         $this->mPrinter = null;
 589                         $this->createErrorPrinter();
 590                         $this->mPrinter->forceDefaultParams();
 591                         $this->printResult( true );
 592                 }
 593         }
 594
 595         /**
 596          * Handle an exception from the ApiBeforeMain hook.
 597          *
 598          * This tries to print the exception as an API response, to be more
 599          * friendly to clients. If it fails, it will rethrow the exception.
 600          *
 601          * @since 1.23
 602          * @param Exception $e
 603          * @throws Exception
 604          */
 605         public static function handleApiBeforeMainException( Exception $e ) {
 606                 ob_start();
 607
 608                 try {
 609                         $main = new self( RequestContext::getMain(), false );
 610                         $main->handleException( $e );
 611                         $main->logRequest( 0, $e );
 612                 } catch ( Exception $e2 ) {
 613                         // Nope, even that didn't work. Punt.
 614                         throw $e;
 615                 }
 616
 617                 // Reset cache headers
 618                 $main->sendCacheHeaders( true );
 619
 620                 ob_end_flush();
 621         }
 622
 623         /**
 624          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 625          *
 626          * If no origin parameter is present, nothing happens.
 627          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 628          * is set and false is returned.
 629          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 630          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 631          * headers are set.
 632          * http://www.w3.org/TR/cors/#resource-requests
 633          * http://www.w3.org/TR/cors/#resource-preflight-requests
 634          *
 635          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 636          */
 637         protected function handleCORS() {
 638                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 639                 if ( $originParam === null ) {
 640                         // No origin parameter, nothing to do
 641                         return true;
 642                 }
 643
 644                 $request = $this->getRequest();
 645                 $response = $request->response();
 646
 647                 // Origin: header is a space-separated list of origins, check all of them
 648                 $originHeader = $request->getHeader( 'Origin' );
 649                 if ( $originHeader === false ) {
 650                         $origins = [];
 651                 } else {
 652                         $originHeader = trim( $originHeader );
 653                         $origins = preg_split( '/\s+/', $originHeader );
 654                 }
 655
 656                 if ( !in_array( $originParam, $origins ) ) {
 657                         // origin parameter set but incorrect
 658                         // Send a 403 response
 659                         $response->statusHeader( 403 );
 660                         $response->header( 'Cache-Control: no-cache' );
 661                         echo "'origin' parameter does not match Origin header\n";
 662
 663                         return false;
 664                 }
 665
 666                 $config = $this->getConfig();
 667                 $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 668                         $originParam,
 669                         $config->get( 'CrossSiteAJAXdomains' ),
 670                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 671                 );
 672
 673                 if ( $matchOrigin ) {
 674                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 675                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 676                         if ( $preflight ) {
 677                                 // This is a CORS preflight request
 678                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 679                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 680                                         return true;
 681                                 }
 682                                 // We allow the actual request to send the following headers
 683                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 684                                 if ( $requestedHeaders !== false ) {
 685                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 686                                                 return true;
 687                                         }
 688                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 689                                 }
 690
 691                                 // We only allow the actual request to be GET or POST
 692                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 693                         }
 694
 695                         $response->header( "Access-Control-Allow-Origin: $originHeader" );
 696                         $response->header( 'Access-Control-Allow-Credentials: true' );
 697                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 698                         $response->header( "Timing-Allow-Origin: $originHeader" );
 699
 700                         if ( !$preflight ) {
 701                                 $response->header(
 702                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 703                                 );
 704                         }
 705                 }
 706
 707                 $this->getOutput()->addVaryHeader( 'Origin' );
 708                 return true;
 709         }
 710
 711         /**
 712          * Attempt to match an Origin header against a set of rules and a set of exceptions
 713          * @param string $value Origin header
 714          * @param array $rules Set of wildcard rules
 715          * @param array $exceptions Set of wildcard rules
 716          * @return bool True if $value matches a rule in $rules and doesn't match
 717          *    any rules in $exceptions, false otherwise
 718          */
 719         protected static function matchOrigin( $value, $rules, $exceptions ) {
 720                 foreach ( $rules as $rule ) {
 721                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 722                                 // Rule matches, check exceptions
 723                                 foreach ( $exceptions as $exc ) {
 724                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 725                                                 return false;
 726                                         }
 727                                 }
 728
 729                                 return true;
 730                         }
 731                 }
 732
 733                 return false;
 734         }
 735
 736         /**
 737          * Attempt to validate the value of Access-Control-Request-Headers against a list
 738          * of headers that we allow the follow up request to send.
 739          *
 740          * @param string $requestedHeaders Comma seperated list of HTTP headers
 741          * @return bool True if all requested headers are in the list of allowed headers
 742          */
 743         protected static function matchRequestedHeaders( $requestedHeaders ) {
 744                 if ( trim( $requestedHeaders ) === '' ) {
 745                         return true;
 746                 }
 747                 $requestedHeaders = explode( ',', $requestedHeaders );
 748                 $allowedAuthorHeaders = array_flip( [
 749                         /* simple headers (see spec) */
 750                         'accept',
 751                         'accept-language',
 752                         'content-language',
 753                         'content-type',
 754                         /* non-authorable headers in XHR, which are however requested by some UAs */
 755                         'accept-encoding',
 756                         'dnt',
 757                         'origin',
 758                         /* MediaWiki whitelist */
 759                         'api-user-agent',
 760                 ] );
 761                 foreach ( $requestedHeaders as $rHeader ) {
 762                         $rHeader = strtolower( trim( $rHeader ) );
 763                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 764                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 765                                 return false;
 766                         }
 767                 }
 768                 return true;
 769         }
 770
 771         /**
 772          * Helper function to convert wildcard string into a regex
 773          * '*' => '.*?'
 774          * '?' => '.'
 775          *
 776          * @param string $wildcard String with wildcards
 777          * @return string Regular expression
 778          */
 779         protected static function wildcardToRegex( $wildcard ) {
 780                 $wildcard = preg_quote( $wildcard, '/' );
 781                 $wildcard = str_replace(
 782                         [ '\*', '\?' ],
 783                         [ '.*?', '.' ],
 784                         $wildcard
 785                 );
 786
 787                 return "/^https?:\/\/$wildcard$/";
 788         }
 789
 790         /**
 791          * Send caching headers
 792          * @param bool $isError Whether an error response is being output
 793          * @since 1.26 added $isError parameter
 794          */
 795         protected function sendCacheHeaders( $isError ) {
 796                 $response = $this->getRequest()->response();
 797                 $out = $this->getOutput();
 798
 799                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 800
 801                 $config = $this->getConfig();
 802
 803                 if ( $config->get( 'VaryOnXFP' ) ) {
 804                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 805                 }
 806
 807                 if ( !$isError && $this->mModule &&
 808                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 809                 ) {
 810                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 811                         if ( $etag !== null ) {
 812                                 $response->header( "ETag: $etag" );
 813                         }
 814                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 815                         if ( $lastMod !== null ) {
 816                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 817                         }
 818                 }
 819
 820                 // The logic should be:
 821                 // $this->mCacheControl['max-age'] is set?
 822                 //    Use it, the module knows better than our guess.
 823                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 824                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 825                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 826                 $maxage = 0;
 827                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 828                         $maxage = $this->mCacheControl['max-age'];
 829                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 830                         $this->mCacheMode !== 'private'
 831                 ) {
 832                         $maxage = $this->getParameter( 'maxage' );
 833                 }
 834                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 835
 836                 if ( $this->mCacheMode == 'private' ) {
 837                         $response->header( "Cache-Control: $privateCache" );
 838                         return;
 839                 }
 840
 841                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 842                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 843                         $out->addVaryHeader( 'Cookie' );
 844                         $response->header( $out->getVaryHeader() );
 845                         if ( $useKeyHeader ) {
 846                                 $response->header( $out->getKeyHeader() );
 847                                 if ( $out->haveCacheVaryCookies() ) {
 848                                         // Logged in, mark this request private
 849                                         $response->header( "Cache-Control: $privateCache" );
 850                                         return;
 851                                 }
 852                                 // Logged out, send normal public headers below
 853                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 854                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 855                                 // Mark request private
 856                                 $response->header( "Cache-Control: $privateCache" );
 857
 858                                 return;
 859                         } // else no Key and anonymous, send public headers below
 860                 }
 861
 862                 // Send public headers
 863                 $response->header( $out->getVaryHeader() );
 864                 if ( $useKeyHeader ) {
 865                         $response->header( $out->getKeyHeader() );
 866                 }
 867
 868                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 869                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 870                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 871                 }
 872                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 873                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 874                 }
 875
 876                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 877                         // Public cache not requested
 878                         // Sending a Vary header in this case is harmless, and protects us
 879                         // against conditional calls of setCacheMaxAge().
 880                         $response->header( "Cache-Control: $privateCache" );
 881
 882                         return;
 883                 }
 884
 885                 $this->mCacheControl['public'] = true;
 886
 887                 // Send an Expires header
 888                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 889                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 890                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 891
 892                 // Construct the Cache-Control header
 893                 $ccHeader = '';
 894                 $separator = '';
 895                 foreach ( $this->mCacheControl as $name => $value ) {
 896                         if ( is_bool( $value ) ) {
 897                                 if ( $value ) {
 898                                         $ccHeader .= $separator . $name;
 899                                         $separator = ', ';
 900                                 }
 901                         } else {
 902                                 $ccHeader .= $separator . "$name=$value";
 903                                 $separator = ', ';
 904                         }
 905                 }
 906
 907                 $response->header( "Cache-Control: $ccHeader" );
 908         }
 909
 910         /**
 911          * Create the printer for error output
 912          */
 913         private function createErrorPrinter() {
 914                 if ( !isset( $this->mPrinter ) ) {
 915                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 916                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 917                                 $value = self::API_DEFAULT_FORMAT;
 918                         }
 919                         $this->mPrinter = $this->createPrinterByName( $value );
 920                 }
 921
 922                 // Printer may not be able to handle errors. This is particularly
 923                 // likely if the module returns something for getCustomPrinter().
 924                 if ( !$this->mPrinter->canPrintErrors() ) {
 925                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 926                 }
 927         }
 928
 929         /**
 930          * Create an error message for the given exception.
 931          *
 932          * If the exception is a UsageException then
 933          * UsageException::getMessageArray() will be called to create the message.
 934          *
 935          * @param Exception $e
 936          * @return array ['code' => 'some string', 'info' => 'some other string']
 937          * @since 1.27
 938          */
 939         protected function errorMessageFromException( $e ) {
 940                 if ( $e instanceof UsageException ) {
 941                         // User entered incorrect parameters - generate error response
 942                         $errMessage = $e->getMessageArray();
 943                 } else {
 944                         $config = $this->getConfig();
 945                         // Something is seriously wrong
 946                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 947                                 $info = 'Database query error';
 948                         } else {
 949                                 $info = "Exception Caught: {$e->getMessage()}";
 950                         }
 951
 952                         $errMessage = [
 953                                 'code' => 'internal_api_error_' . get_class( $e ),
 954                                 'info' => '[' . WebRequest::getRequestId() . '] ' . $info,
 955                         ];
 956                 }
 957                 return $errMessage;
 958         }
 959
 960         /**
 961          * Replace the result data with the information about an exception.
 962          * Returns the error code
 963          * @param Exception $e
 964          * @return string
 965          */
 966         protected function substituteResultWithError( $e ) {
 967                 $result = $this->getResult();
 968                 $config = $this->getConfig();
 969
 970                 $errMessage = $this->errorMessageFromException( $e );
 971                 if ( $e instanceof UsageException ) {
 972                         // User entered incorrect parameters - generate error response
 973                         $link = wfExpandUrl( wfScript( 'api' ) );
 974                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
 975                 } else {
 976                         // Something is seriously wrong
 977                         if ( $config->get( 'ShowExceptionDetails' ) ) {
 978                                 ApiResult::setContentValue(
 979                                         $errMessage,
 980                                         'trace',
 981                                         MWExceptionHandler::getRedactedTraceAsString( $e )
 982                                 );
 983                         }
 984                 }
 985
 986                 // Remember all the warnings to re-add them later
 987                 $warnings = $result->getResultData( [ 'warnings' ] );
 988
 989                 $result->reset();
 990                 // Re-add the id
 991                 $requestid = $this->getParameter( 'requestid' );
 992                 if ( !is_null( $requestid ) ) {
 993                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
 994                 }
 995                 if ( $config->get( 'ShowHostnames' ) ) {
 996                         // servedby is especially useful when debugging errors
 997                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
 998                 }
 999                 if ( $warnings !== null ) {
1000                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1001                 }
1002
1003                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
1004
1005                 return $errMessage['code'];
1006         }
1007
1008         /**
1009          * Set up for the execution.
1010          * @return array
1011          */
1012         protected function setupExecuteAction() {
1013                 // First add the id to the top element
1014                 $result = $this->getResult();
1015                 $requestid = $this->getParameter( 'requestid' );
1016                 if ( !is_null( $requestid ) ) {
1017                         $result->addValue( null, 'requestid', $requestid );
1018                 }
1019
1020                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1021                         $servedby = $this->getParameter( 'servedby' );
1022                         if ( $servedby ) {
1023                                 $result->addValue( null, 'servedby', wfHostname() );
1024                         }
1025                 }
1026
1027                 if ( $this->getParameter( 'curtimestamp' ) ) {
1028                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1029                                 ApiResult::NO_SIZE_CHECK );
1030                 }
1031
1032                 $params = $this->extractRequestParams();
1033
1034                 $this->mAction = $params['action'];
1035
1036                 if ( !is_string( $this->mAction ) ) {
1037                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1038                 }
1039
1040                 return $params;
1041         }
1042
1043         /**
1044          * Set up the module for response
1045          * @return ApiBase The module that will handle this action
1046          * @throws MWException
1047          * @throws UsageException
1048          */
1049         protected function setupModule() {
1050                 // Instantiate the module requested by the user
1051                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1052                 if ( $module === null ) {
1053                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1054                 }
1055                 $moduleParams = $module->extractRequestParams();
1056
1057                 // Check token, if necessary
1058                 if ( $module->needsToken() === true ) {
1059                         throw new MWException(
1060                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1061                                 'See documentation for ApiBase::needsToken for details.'
1062                         );
1063                 }
1064                 if ( $module->needsToken() ) {
1065                         if ( !$module->mustBePosted() ) {
1066                                 throw new MWException(
1067                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1068                                 );
1069                         }
1070
1071                         if ( !isset( $moduleParams['token'] ) ) {
1072                                 $this->dieUsageMsg( [ 'missingparam', 'token' ] );
1073                         }
1074
1075                         if ( !$this->getConfig()->get( 'DebugAPI' ) &&
1076                                 array_key_exists(
1077                                         $module->encodeParamName( 'token' ),
1078                                         $this->getRequest()->getQueryValues()
1079                                 )
1080                         ) {
1081                                 $this->dieUsage(
1082                                         "The '{$module->encodeParamName( 'token' )}' parameter was " .
1083                                                 'found in the query string, but must be in the POST body',
1084                                         'mustposttoken'
1085                                 );
1086                         }
1087
1088                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1089                                 $this->dieUsageMsg( 'sessionfailure' );
1090                         }
1091                 }
1092
1093                 return $module;
1094         }
1095
1096         /**
1097          * Check the max lag if necessary
1098          * @param ApiBase $module Api module being used
1099          * @param array $params Array an array containing the request parameters.
1100          * @return bool True on success, false should exit immediately
1101          */
1102         protected function checkMaxLag( $module, $params ) {
1103                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1104                         $maxLag = $params['maxlag'];
1105                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1106                         if ( $lag > $maxLag ) {
1107                                 $response = $this->getRequest()->response();
1108
1109                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1110                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1111
1112                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1113                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1114                                 }
1115
1116                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1117                         }
1118                 }
1119
1120                 return true;
1121         }
1122
1123         /**
1124          * Check selected RFC 7232 precondition headers
1125          *
1126          * RFC 7232 envisions a particular model where you send your request to "a
1127          * resource", and for write requests that you can read "the resource" by
1128          * changing the method to GET. When the API receives a GET request, it
1129          * works out even though "the resource" from RFC 7232's perspective might
1130          * be many resources from MediaWiki's perspective. But it totally fails for
1131          * a POST, since what HTTP sees as "the resource" is probably just
1132          * "/api.php" with all the interesting bits in the body.
1133          *
1134          * Therefore, we only support RFC 7232 precondition headers for GET (and
1135          * HEAD). That means we don't need to bother with If-Match and
1136          * If-Unmodified-Since since they only apply to modification requests.
1137          *
1138          * And since we don't support Range, If-Range is ignored too.
1139          *
1140          * @since 1.26
1141          * @param ApiBase $module Api module being used
1142          * @return bool True on success, false should exit immediately
1143          */
1144         protected function checkConditionalRequestHeaders( $module ) {
1145                 if ( $this->mInternalMode ) {
1146                         // No headers to check in internal mode
1147                         return true;
1148                 }
1149
1150                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1151                         // Don't check POSTs
1152                         return true;
1153                 }
1154
1155                 $return304 = false;
1156
1157                 $ifNoneMatch = array_diff(
1158                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1159                         [ '' ]
1160                 );
1161                 if ( $ifNoneMatch ) {
1162                         if ( $ifNoneMatch === [ '*' ] ) {
1163                                 // API responses always "exist"
1164                                 $etag = '*';
1165                         } else {
1166                                 $etag = $module->getConditionalRequestData( 'etag' );
1167                         }
1168                 }
1169                 if ( $ifNoneMatch && $etag !== null ) {
1170                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1171                         $match = array_map( function ( $s ) {
1172                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1173                         }, $ifNoneMatch );
1174                         $return304 = in_array( $test, $match, true );
1175                 } else {
1176                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1177
1178                         // Some old browsers sends sizes after the date, like this:
1179                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1180                         // Ignore that.
1181                         $i = strpos( $value, ';' );
1182                         if ( $i !== false ) {
1183                                 $value = trim( substr( $value, 0, $i ) );
1184                         }
1185
1186                         if ( $value !== '' ) {
1187                                 try {
1188                                         $ts = new MWTimestamp( $value );
1189                                         if (
1190                                                 // RFC 7231 IMF-fixdate
1191                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1192                                                 // RFC 850
1193                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1194                                                 // asctime (with and without space-padded day)
1195                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1196                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1197                                         ) {
1198                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1199                                                 if ( $lastMod !== null ) {
1200                                                         // Mix in some MediaWiki modification times
1201                                                         $modifiedTimes = [
1202                                                                 'page' => $lastMod,
1203                                                                 'user' => $this->getUser()->getTouched(),
1204                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1205                                                         ];
1206                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1207                                                                 // T46570: the core page itself may not change, but resources might
1208                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1209                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1210                                                                 );
1211                                                         }
1212                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1213                                                         $lastMod = max( $modifiedTimes );
1214                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1215                                                 }
1216                                         }
1217                                 } catch ( TimestampException $e ) {
1218                                         // Invalid timestamp, ignore it
1219                                 }
1220                         }
1221                 }
1222
1223                 if ( $return304 ) {
1224                         $this->getRequest()->response()->statusHeader( 304 );
1225
1226                         // Avoid outputting the compressed representation of a zero-length body
1227                         MediaWiki\suppressWarnings();
1228                         ini_set( 'zlib.output_compression', 0 );
1229                         MediaWiki\restoreWarnings();
1230                         wfClearOutputBuffers();
1231
1232                         return false;
1233                 }
1234
1235                 return true;
1236         }
1237
1238         /**
1239          * Check for sufficient permissions to execute
1240          * @param ApiBase $module An Api module
1241          */
1242         protected function checkExecutePermissions( $module ) {
1243                 $user = $this->getUser();
1244                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1245                         !$user->isAllowed( 'read' )
1246                 ) {
1247                         $this->dieUsageMsg( 'readrequired' );
1248                 }
1249
1250                 if ( $module->isWriteMode() ) {
1251                         if ( !$this->mEnableWrite ) {
1252                                 $this->dieUsageMsg( 'writedisabled' );
1253                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1254                                 $this->dieUsageMsg( 'writerequired' );
1255                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1256                                 $this->dieUsage(
1257                                         'Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules',
1258                                         'promised-nonwrite-api'
1259                                 );
1260                         }
1261
1262                         $this->checkReadOnly( $module );
1263                 }
1264
1265                 // Allow extensions to stop execution for arbitrary reasons.
1266                 $message = false;
1267                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1268                         $this->dieUsageMsg( $message );
1269                 }
1270         }
1271
1272         /**
1273          * Check if the DB is read-only for this user
1274          * @param ApiBase $module An Api module
1275          */
1276         protected function checkReadOnly( $module ) {
1277                 if ( wfReadOnly() ) {
1278                         $this->dieReadOnly();
1279                 }
1280
1281                 if ( $module->isWriteMode()
1282                         && in_array( 'bot', $this->getUser()->getGroups() )
1283                         && wfGetLB()->getServerCount() > 1
1284                 ) {
1285                         $this->checkBotReadOnly();
1286                 }
1287         }
1288
1289         /**
1290          * Check whether we are readonly for bots
1291          */
1292         private function checkBotReadOnly() {
1293                 // Figure out how many servers have passed the lag threshold
1294                 $numLagged = 0;
1295                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1296                 $laggedServers = [];
1297                 $loadBalancer = wfGetLB();
1298                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1299                         if ( $lag > $lagLimit ) {
1300                                 ++$numLagged;
1301                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1302                         }
1303                 }
1304
1305                 // If a majority of slaves are too lagged then disallow writes
1306                 $slaveCount = wfGetLB()->getServerCount() - 1;
1307                 if ( $numLagged >= ceil( $slaveCount / 2 ) ) {
1308                         $laggedServers = implode( ', ', $laggedServers );
1309                         wfDebugLog(
1310                                 'api-readonly',
1311                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1312                         );
1313
1314                         $parsed = $this->parseMsg( [ 'readonlytext' ] );
1315                         $this->dieUsage(
1316                                 $parsed['info'],
1317                                 $parsed['code'],
1318                                 /* http error */
1319                                 0,
1320                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1321                         );
1322                 }
1323         }
1324
1325         /**
1326          * Check asserts of the user's rights
1327          * @param array $params
1328          */
1329         protected function checkAsserts( $params ) {
1330                 if ( isset( $params['assert'] ) ) {
1331                         $user = $this->getUser();
1332                         switch ( $params['assert'] ) {
1333                                 case 'user':
1334                                         if ( $user->isAnon() ) {
1335                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1336                                         }
1337                                         break;
1338                                 case 'bot':
1339                                         if ( !$user->isAllowed( 'bot' ) ) {
1340                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1341                                         }
1342                                         break;
1343                         }
1344                 }
1345         }
1346
1347         /**
1348          * Check POST for external response and setup result printer
1349          * @param ApiBase $module An Api module
1350          * @param array $params An array with the request parameters
1351          */
1352         protected function setupExternalResponse( $module, $params ) {
1353                 $request = $this->getRequest();
1354                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1355                         // Module requires POST. GET request might still be allowed
1356                         // if $wgDebugApi is true, otherwise fail.
1357                         $this->dieUsageMsgOrDebug( [ 'mustbeposted', $this->mAction ] );
1358                 }
1359
1360                 // See if custom printer is used
1361                 $this->mPrinter = $module->getCustomPrinter();
1362                 if ( is_null( $this->mPrinter ) ) {
1363                         // Create an appropriate printer
1364                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1365                 }
1366
1367                 if ( $request->getProtocol() === 'http' && (
1368                         $request->getSession()->shouldForceHTTPS() ||
1369                         ( $this->getUser()->isLoggedIn() &&
1370                                 $this->getUser()->requiresHTTPS() )
1371                 ) ) {
1372                         $this->logFeatureUsage( 'https-expected' );
1373                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1374                 }
1375         }
1376
1377         /**
1378          * Execute the actual module, without any error handling
1379          */
1380         protected function executeAction() {
1381                 $params = $this->setupExecuteAction();
1382                 $module = $this->setupModule();
1383                 $this->mModule = $module;
1384
1385                 if ( !$this->mInternalMode ) {
1386                         $this->setRequestExpectations( $module );
1387                 }
1388
1389                 $this->checkExecutePermissions( $module );
1390
1391                 if ( !$this->checkMaxLag( $module, $params ) ) {
1392                         return;
1393                 }
1394
1395                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1396                         return;
1397                 }
1398
1399                 if ( !$this->mInternalMode ) {
1400                         $this->setupExternalResponse( $module, $params );
1401                 }
1402
1403                 $this->checkAsserts( $params );
1404
1405                 // Execute
1406                 $module->execute();
1407                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1408
1409                 $this->reportUnusedParams();
1410
1411                 if ( !$this->mInternalMode ) {
1412                         // append Debug information
1413                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1414
1415                         // Print result data
1416                         $this->printResult( false );
1417                 }
1418         }
1419
1420         /**
1421          * Set database connection, query, and write expectations given this module request
1422          * @param ApiBase $module
1423          */
1424         protected function setRequestExpectations( ApiBase $module ) {
1425                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1426                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1427                 if ( $this->getRequest()->hasSafeMethod() ) {
1428                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1429                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1430                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1431                         $this->getRequest()->markAsSafeRequest();
1432                 } else {
1433                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1434                 }
1435         }
1436
1437         /**
1438          * Log the preceding request
1439          * @param float $time Time in seconds
1440          * @param Exception $e Exception caught while processing the request
1441          */
1442         protected function logRequest( $time, $e = null ) {
1443                 $request = $this->getRequest();
1444                 $logCtx = [
1445                         'ts' => time(),
1446                         'ip' => $request->getIP(),
1447                         'userAgent' => $this->getUserAgent(),
1448                         'wiki' => wfWikiID(),
1449                         'timeSpentBackend' => (int) round( $time * 1000 ),
1450                         'hadError' => $e !== null,
1451                         'errorCodes' => [],
1452                         'params' => [],
1453                 ];
1454
1455                 if ( $e ) {
1456                         $logCtx['errorCodes'][] = $this->errorMessageFromException( $e )['code'];
1457                 }
1458
1459                 // Construct space separated message for 'api' log channel
1460                 $msg = "API {$request->getMethod()} " .
1461                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1462                         " {$logCtx['ip']} " .
1463                         "T={$logCtx['timeSpentBackend']}ms";
1464
1465                 foreach ( $this->getParamsUsed() as $name ) {
1466                         $value = $request->getVal( $name );
1467                         if ( $value === null ) {
1468                                 continue;
1469                         }
1470
1471                         if ( strlen( $value ) > 256 ) {
1472                                 $value = substr( $value, 0, 256 );
1473                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1474                         } else {
1475                                 $encValue = $this->encodeRequestLogValue( $value );
1476                         }
1477
1478                         $logCtx['params'][$name] = $value;
1479                         $msg .= " {$name}={$encValue}";
1480                 }
1481
1482                 wfDebugLog( 'api', $msg, 'private' );
1483                 // ApiAction channel is for structured data consumers
1484                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1485         }
1486
1487         /**
1488          * Encode a value in a format suitable for a space-separated log line.
1489          * @param string $s
1490          * @return string
1491          */
1492         protected function encodeRequestLogValue( $s ) {
1493                 static $table;
1494                 if ( !$table ) {
1495                         $chars = ';@$!*(),/:';
1496                         $numChars = strlen( $chars );
1497                         for ( $i = 0; $i < $numChars; $i++ ) {
1498                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1499                         }
1500                 }
1501
1502                 return strtr( rawurlencode( $s ), $table );
1503         }
1504
1505         /**
1506          * Get the request parameters used in the course of the preceding execute() request
1507          * @return array
1508          */
1509         protected function getParamsUsed() {
1510                 return array_keys( $this->mParamsUsed );
1511         }
1512
1513         /**
1514          * Mark parameters as used
1515          * @param string|string[] $params
1516          */
1517         public function markParamsUsed( $params ) {
1518                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1519         }
1520
1521         /**
1522          * Get a request value, and register the fact that it was used, for logging.
1523          * @param string $name
1524          * @param mixed $default
1525          * @return mixed
1526          */
1527         public function getVal( $name, $default = null ) {
1528                 $this->mParamsUsed[$name] = true;
1529
1530                 $ret = $this->getRequest()->getVal( $name );
1531                 if ( $ret === null ) {
1532                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1533                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1534                                 // array.
1535                                 $this->setWarning(
1536                                         "Parameter '$name' uses unsupported PHP array syntax"
1537                                 );
1538                         }
1539                         $ret = $default;
1540                 }
1541                 return $ret;
1542         }
1543
1544         /**
1545          * Get a boolean request value, and register the fact that the parameter
1546          * was used, for logging.
1547          * @param string $name
1548          * @return bool
1549          */
1550         public function getCheck( $name ) {
1551                 return $this->getVal( $name, null ) !== null;
1552         }
1553
1554         /**
1555          * Get a request upload, and register the fact that it was used, for logging.
1556          *
1557          * @since 1.21
1558          * @param string $name Parameter name
1559          * @return WebRequestUpload
1560          */
1561         public function getUpload( $name ) {
1562                 $this->mParamsUsed[$name] = true;
1563
1564                 return $this->getRequest()->getUpload( $name );
1565         }
1566
1567         /**
1568          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1569          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1570          */
1571         protected function reportUnusedParams() {
1572                 $paramsUsed = $this->getParamsUsed();
1573                 $allParams = $this->getRequest()->getValueNames();
1574
1575                 if ( !$this->mInternalMode ) {
1576                         // Printer has not yet executed; don't warn that its parameters are unused
1577                         $printerParams = array_map(
1578                                 [ $this->mPrinter, 'encodeParamName' ],
1579                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1580                         );
1581                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1582                 } else {
1583                         $unusedParams = array_diff( $allParams, $paramsUsed );
1584                 }
1585
1586                 if ( count( $unusedParams ) ) {
1587                         $s = count( $unusedParams ) > 1 ? 's' : '';
1588                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1589                 }
1590         }
1591
1592         /**
1593          * Print results using the current printer
1594          *
1595          * @param bool $isError
1596          */
1597         protected function printResult( $isError ) {
1598                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1599                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1600                 }
1601
1602                 $printer = $this->mPrinter;
1603                 $printer->initPrinter( false );
1604                 $printer->execute();
1605                 $printer->closePrinter();
1606         }
1607
1608         /**
1609          * @return bool
1610          */
1611         public function isReadMode() {
1612                 return false;
1613         }
1614
1615         /**
1616          * See ApiBase for description.
1617          *
1618          * @return array
1619          */
1620         public function getAllowedParams() {
1621                 return [
1622                         'action' => [
1623                                 ApiBase::PARAM_DFLT => 'help',
1624                                 ApiBase::PARAM_TYPE => 'submodule',
1625                         ],
1626                         'format' => [
1627                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1628                                 ApiBase::PARAM_TYPE => 'submodule',
1629                         ],
1630                         'maxlag' => [
1631                                 ApiBase::PARAM_TYPE => 'integer'
1632                         ],
1633                         'smaxage' => [
1634                                 ApiBase::PARAM_TYPE => 'integer',
1635                                 ApiBase::PARAM_DFLT => 0
1636                         ],
1637                         'maxage' => [
1638                                 ApiBase::PARAM_TYPE => 'integer',
1639                                 ApiBase::PARAM_DFLT => 0
1640                         ],
1641                         'assert' => [
1642                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1643                         ],
1644                         'requestid' => null,
1645                         'servedby' => false,
1646                         'curtimestamp' => false,
1647                         'origin' => null,
1648                         'uselang' => [
1649                                 ApiBase::PARAM_DFLT => 'user',
1650                         ],
1651                 ];
1652         }
1653
1654         /** @see ApiBase::getExamplesMessages() */
1655         protected function getExamplesMessages() {
1656                 return [
1657                         'action=help'
1658                                 => 'apihelp-help-example-main',
1659                         'action=help&recursivesubmodules=1'
1660                                 => 'apihelp-help-example-recursive',
1661                 ];
1662         }
1663
1664         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1665                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1666                 // reindex the array to get 'permissions' in the right place.
1667                 $oldHelp = $help;
1668                 $help = [];
1669                 foreach ( $oldHelp as $k => $v ) {
1670                         if ( $k === 'submodules' ) {
1671                                 $help['permissions'] = '';
1672                         }
1673                         $help[$k] = $v;
1674                 }
1675                 $help['datatypes'] = '';
1676                 $help['credits'] = '';
1677
1678                 // Fill 'permissions'
1679                 $help['permissions'] .= Html::openElement( 'div',
1680                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1681                 $m = $this->msg( 'api-help-permissions' );
1682                 if ( !$m->isDisabled() ) {
1683                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1684                                 $m->numParams( count( self::$mRights ) )->parse()
1685                         );
1686                 }
1687                 $help['permissions'] .= Html::openElement( 'dl' );
1688                 foreach ( self::$mRights as $right => $rightMsg ) {
1689                         $help['permissions'] .= Html::element( 'dt', null, $right );
1690
1691                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1692                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1693
1694                         $groups = array_map( function ( $group ) {
1695                                 return $group == '*' ? 'all' : $group;
1696                         }, User::getGroupsWithPermission( $right ) );
1697
1698                         $help['permissions'] .= Html::rawElement( 'dd', null,
1699                                 $this->msg( 'api-help-permissions-granted-to' )
1700                                         ->numParams( count( $groups ) )
1701                                         ->params( $this->getLanguage()->commaList( $groups ) )
1702                                         ->parse()
1703                         );
1704                 }
1705                 $help['permissions'] .= Html::closeElement( 'dl' );
1706                 $help['permissions'] .= Html::closeElement( 'div' );
1707
1708                 // Fill 'datatypes' and 'credits', if applicable
1709                 if ( empty( $options['nolead'] ) ) {
1710                         $level = $options['headerlevel'];
1711                         $tocnumber = &$options['tocnumber'];
1712
1713                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1714
1715                         // Add an additional span with sanitized ID
1716                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1717                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1718                                         $header;
1719                         }
1720                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1721                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1722                                 $header
1723                         );
1724                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1725                         if ( !isset( $tocData['main/datatypes'] ) ) {
1726                                 $tocnumber[$level]++;
1727                                 $tocData['main/datatypes'] = [
1728                                         'toclevel' => count( $tocnumber ),
1729                                         'level' => $level,
1730                                         'anchor' => 'main/datatypes',
1731                                         'line' => $header,
1732                                         'number' => implode( '.', $tocnumber ),
1733                                         'index' => false,
1734                                 ];
1735                         }
1736
1737                         // Add an additional span with sanitized ID
1738                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1739                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1740                                         $header;
1741                         }
1742                         $header = $this->msg( 'api-credits-header' )->parse();
1743                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1744                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1745                                 $header
1746                         );
1747                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1748                         if ( !isset( $tocData['main/credits'] ) ) {
1749                                 $tocnumber[$level]++;
1750                                 $tocData['main/credits'] = [
1751                                         'toclevel' => count( $tocnumber ),
1752                                         'level' => $level,
1753                                         'anchor' => 'main/credits',
1754                                         'line' => $header,
1755                                         'number' => implode( '.', $tocnumber ),
1756                                         'index' => false,
1757                                 ];
1758                         }
1759                 }
1760         }
1761
1762         private $mCanApiHighLimits = null;
1763
1764         /**
1765          * Check whether the current user is allowed to use high limits
1766          * @return bool
1767          */
1768         public function canApiHighLimits() {
1769                 if ( !isset( $this->mCanApiHighLimits ) ) {
1770                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1771                 }
1772
1773                 return $this->mCanApiHighLimits;
1774         }
1775
1776         /**
1777          * Overrides to return this instance's module manager.
1778          * @return ApiModuleManager
1779          */
1780         public function getModuleManager() {
1781                 return $this->mModuleMgr;
1782         }
1783
1784         /**
1785          * Fetches the user agent used for this request
1786          *
1787          * The value will be the combination of the 'Api-User-Agent' header (if
1788          * any) and the standard User-Agent header (if any).
1789          *
1790          * @return string
1791          */
1792         public function getUserAgent() {
1793                 return trim(
1794                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1795                         $this->getRequest()->getHeader( 'User-agent' )
1796                 );
1797         }
1798
1799         /************************************************************************//**
1800          * @name   Deprecated
1801          * @{
1802          */
1803
1804         /**
1805          * Sets whether the pretty-printer should format *bold* and $italics$
1806          *
1807          * @deprecated since 1.25
1808          * @param bool $help
1809          */
1810         public function setHelp( $help = true ) {
1811                 wfDeprecated( __METHOD__, '1.25' );
1812                 $this->mPrinter->setHelp( $help );
1813         }
1814
1815         /**
1816          * Override the parent to generate help messages for all available modules.
1817          *
1818          * @deprecated since 1.25
1819          * @return string
1820          */
1821         public function makeHelpMsg() {
1822                 wfDeprecated( __METHOD__, '1.25' );
1823
1824                 $this->setHelp();
1825                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1826
1827                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1828                         wfMemcKey(
1829                                 'apihelp',
1830                                 $this->getModuleName(),
1831                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1832                         ),
1833                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1834                         [ $this, 'reallyMakeHelpMsg' ]
1835                 );
1836         }
1837
1838         /**
1839          * @deprecated since 1.25
1840          * @return mixed|string
1841          */
1842         public function reallyMakeHelpMsg() {
1843                 wfDeprecated( __METHOD__, '1.25' );
1844                 $this->setHelp();
1845
1846                 // Use parent to make default message for the main module
1847                 $msg = parent::makeHelpMsg();
1848
1849                 $asterisks = str_repeat( '*** ', 14 );
1850                 $msg .= "\n\n$asterisks Modules  $asterisks\n\n";
1851
1852                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1853                         $module = $this->mModuleMgr->getModule( $name );
1854                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1855
1856                         $msg2 = $module->makeHelpMsg();
1857                         if ( $msg2 !== false ) {
1858                                 $msg .= $msg2;
1859                         }
1860                         $msg .= "\n";
1861                 }
1862
1863                 $msg .= "\n$asterisks Permissions $asterisks\n\n";
1864                 foreach ( self::$mRights as $right => $rightMsg ) {
1865                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1866                                 ->useDatabase( false )
1867                                 ->inLanguage( 'en' )
1868                                 ->text();
1869                         $groups = User::getGroupsWithPermission( $right );
1870                         $msg .= '* ' . $right . " *\n  $rightsMsg" .
1871                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1872                 }
1873
1874                 $msg .= "\n$asterisks Formats  $asterisks\n\n";
1875                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1876                         $module = $this->mModuleMgr->getModule( $name );
1877                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1878                         $msg2 = $module->makeHelpMsg();
1879                         if ( $msg2 !== false ) {
1880                                 $msg .= $msg2;
1881                         }
1882                         $msg .= "\n";
1883                 }
1884
1885                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1886                 $credits = str_replace( "\n", "\n   ", $credits );
1887                 $msg .= "\n*** Credits: ***\n   $credits\n";
1888
1889                 return $msg;
1890         }
1891
1892         /**
1893          * @deprecated since 1.25
1894          * @param ApiBase $module
1895          * @param string $paramName What type of request is this? e.g. action,
1896          *    query, list, prop, meta, format
1897          * @return string
1898          */
1899         public static function makeHelpMsgHeader( $module, $paramName ) {
1900                 wfDeprecated( __METHOD__, '1.25' );
1901                 $modulePrefix = $module->getModulePrefix();
1902                 if ( strval( $modulePrefix ) !== '' ) {
1903                         $modulePrefix = "($modulePrefix) ";
1904                 }
1905
1906                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1907         }
1908
1909         /**@}*/
1910
1911 }
1912
1913 /**
1914  * This exception will be thrown when dieUsage is called to stop module execution.
1915  *
1916  * @ingroup API
1917  */
1918 class UsageException extends MWException {
1919
1920         private $mCodestr;
1921
1922         /**
1923          * @var null|array
1924          */
1925         private $mExtraData;
1926
1927         /**
1928          * @param string $message
1929          * @param string $codestr
1930          * @param int $code
1931          * @param array|null $extradata
1932          */
1933         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1934                 parent::__construct( $message, $code );
1935                 $this->mCodestr = $codestr;
1936                 $this->mExtraData = $extradata;
1937
1938                 // This should never happen, so throw an exception about it that will
1939                 // hopefully get logged with a backtrace (T138585)
1940                 if ( !is_string( $codestr ) || $codestr === '' ) {
1941                         throw new InvalidArgumentException( 'Invalid $codestr, was ' .
1942                                 ( $codestr === '' ? 'empty string' : gettype( $codestr ) )
1943                         );
1944                 }
1945         }
1946
1947         /**
1948          * @return string
1949          */
1950         public function getCodeString() {
1951                 return $this->mCodestr;
1952         }
1953
1954         /**
1955          * @return array
1956          */
1957         public function getMessageArray() {
1958                 $result = [
1959                         'code' => $this->mCodestr,
1960                         'info' => $this->getMessage()
1961                 ];
1962                 if ( is_array( $this->mExtraData ) ) {
1963                         $result = array_merge( $result, $this->mExtraData );
1964                 }
1965
1966                 return $result;
1967         }
1968
1969         /**
1970          * @return string
1971          */
1972         public function __toString() {
1973                 return "{$this->getCodeString()}: {$this->getMessage()}";
1974         }
1975 }
1976
1977 /**
1978  * For really cool vim folding this needs to be at the end:
1979  * vim: foldmarker=@{,@} foldmethod=marker
1980  */