includes/api/ApiMain.php

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