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