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