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