includes/api/ApiMain.php

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