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         /**
  44          * When no format parameter is given, this format will be used
  45          */
  46         const API_DEFAULT_FORMAT = 'xmlfm';
  47
  48         /**
  49          * List of available modules: action name => module class
  50          */
  51         private static $Modules = array(
  52                 'login' => 'ApiLogin',
  53                 'logout' => 'ApiLogout',
  54                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'opensearch' => 'ApiOpenSearch',
  58                 'feedcontributions' => 'ApiFeedContributions',
  59                 'feedwatchlist' => 'ApiFeedWatchlist',
  60                 'help' => 'ApiHelp',
  61                 'paraminfo' => 'ApiParamInfo',
  62                 'rsd' => 'ApiRsd',
  63                 'compare' => 'ApiComparePages',
  64                 'tokens' => 'ApiTokens',
  65
  66                 // Write modules
  67                 'purge' => 'ApiPurge',
  68                 'rollback' => 'ApiRollback',
  69                 'delete' => 'ApiDelete',
  70                 'undelete' => 'ApiUndelete',
  71                 'protect' => 'ApiProtect',
  72                 'block' => 'ApiBlock',
  73                 'unblock' => 'ApiUnblock',
  74                 'move' => 'ApiMove',
  75                 'edit' => 'ApiEditPage',
  76                 'upload' => 'ApiUpload',
  77                 'filerevert' => 'ApiFileRevert',
  78                 'emailuser' => 'ApiEmailUser',
  79                 'watch' => 'ApiWatch',
  80                 'patrol' => 'ApiPatrol',
  81                 'import' => 'ApiImport',
  82                 'userrights' => 'ApiUserrights',
  83                 'options' => 'ApiOptions',
  84         );
  85
  86         /**
  87          * List of available formats: format name => format class
  88          */
  89         private static $Formats = array(
  90                 'json' => 'ApiFormatJson',
  91                 'jsonfm' => 'ApiFormatJson',
  92                 'php' => 'ApiFormatPhp',
  93                 'phpfm' => 'ApiFormatPhp',
  94                 'wddx' => 'ApiFormatWddx',
  95                 'wddxfm' => 'ApiFormatWddx',
  96                 'xml' => 'ApiFormatXml',
  97                 'xmlfm' => 'ApiFormatXml',
  98                 'yaml' => 'ApiFormatYaml',
  99                 'yamlfm' => 'ApiFormatYaml',
 100                 'rawfm' => 'ApiFormatJson',
 101                 'txt' => 'ApiFormatTxt',
 102                 'txtfm' => 'ApiFormatTxt',
 103                 'dbg' => 'ApiFormatDbg',
 104                 'dbgfm' => 'ApiFormatDbg',
 105                 'dump' => 'ApiFormatDump',
 106                 'dumpfm' => 'ApiFormatDump',
 107         );
 108
 109         /**
 110          * List of user roles that are specifically relevant to the API.
 111          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 112          *                           'params' => array ( $someVarToSubst ) ),
 113          *                          );
 114          */
 115         private static $mRights = array(
 116                 'writeapi' => array(
 117                         'msg' => 'Use of the write API',
 118                         'params' => array()
 119                 ),
 120                 'apihighlimits' => array(
 121                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 122                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 123                 )
 124         );
 125
 126         /**
 127          * @var ApiFormatBase
 128          */
 129         private $mPrinter;
 130
 131         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 132         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 133         private $mInternalMode, $mSquidMaxage, $mModule;
 134
 135         private $mCacheMode = 'private';
 136         private $mCacheControl = array();
 137
 138         /**
 139          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 140          *
 141          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 142          * @param $enableWrite bool should be set to true if the api may modify data
 143          */
 144         public function __construct( $context = null, $enableWrite = false ) {
 145                 if ( $context === null ) {
 146                         $context = RequestContext::getMain();
 147                 } elseif ( $context instanceof WebRequest ) {
 148                         // BC for pre-1.19
 149                         $request = $context;
 150                         $context = RequestContext::getMain();
 151                 }
 152                 // We set a derivative context so we can change stuff later
 153                 $this->setContext( new DerivativeContext( $context ) );
 154
 155                 if ( isset( $request ) ) {
 156                         $this->getContext()->setRequest( $request );
 157                 }
 158
 159                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 160
 161                 // Special handling for the main module: $parent === $this
 162                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 163
 164                 if ( !$this->mInternalMode ) {
 165                         // Impose module restrictions.
 166                         // If the current user cannot read,
 167                         // Remove all modules other than login
 168                         global $wgUser;
 169
 170                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 171                                 // JSON callback allows cross-site reads.
 172                                 // For safety, strip user credentials.
 173                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 174                                 $wgUser = new User();
 175                                 $this->getContext()->setUser( $wgUser );
 176                         }
 177                 }
 178
 179                 global $wgAPIModules; // extension modules
 180                 $this->mModules = $wgAPIModules + self::$Modules;
 181
 182                 $this->mModuleNames = array_keys( $this->mModules );
 183                 $this->mFormats = self::$Formats;
 184                 $this->mFormatNames = array_keys( $this->mFormats );
 185
 186                 $this->mResult = new ApiResult( $this );
 187                 $this->mShowVersions = false;
 188                 $this->mEnableWrite = $enableWrite;
 189
 190                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 191                 $this->mCommit = false;
 192         }
 193
 194         /**
 195          * Return true if the API was started by other PHP code using FauxRequest
 196          * @return bool
 197          */
 198         public function isInternalMode() {
 199                 return $this->mInternalMode;
 200         }
 201
 202         /**
 203          * Get the ApiResult object associated with current request
 204          *
 205          * @return ApiResult
 206          */
 207         public function getResult() {
 208                 return $this->mResult;
 209         }
 210
 211         /**
 212          * Get the API module object. Only works after executeAction()
 213          *
 214          * @return ApiBase
 215          */
 216         public function getModule() {
 217                 return $this->mModule;
 218         }
 219
 220         /**
 221          * Get the result formatter object. Only works after setupExecuteAction()
 222          *
 223          * @return ApiFormatBase
 224          */
 225         public function getPrinter() {
 226                 return $this->mPrinter;
 227         }
 228
 229         /**
 230          * Set how long the response should be cached.
 231          *
 232          * @param $maxage
 233          */
 234         public function setCacheMaxAge( $maxage ) {
 235                 $this->setCacheControl( array(
 236                         'max-age' => $maxage,
 237                         's-maxage' => $maxage
 238                 ) );
 239         }
 240
 241         /**
 242          * Set the type of caching headers which will be sent.
 243          *
 244          * @param $mode String One of:
 245          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 246          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 247          *         not provided by any of these means, the object will be private.
 248          *    - 'private':    Cache this object only in private client-side caches.
 249          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 250          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 251          *         set consistently for a given URL, it cannot be set differently depending on
 252          *         things like the contents of the database, or whether the user is logged in.
 253          *
 254          *  If the wiki does not allow anonymous users to read it, the mode set here
 255          *  will be ignored, and private caching headers will always be sent. In other words,
 256          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 257          *  view.
 258          *
 259          *  For user-dependent data, the private mode should generally be used. The
 260          *  anon-public-user-private mode should only be used where there is a particularly
 261          *  good performance reason for caching the anonymous response, but where the
 262          *  response to logged-in users may differ, or may contain private data.
 263          *
 264          *  If this function is never called, then the default will be the private mode.
 265          */
 266         public function setCacheMode( $mode ) {
 267                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 268                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 269                         // Ignore for forwards-compatibility
 270                         return;
 271                 }
 272
 273                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 274                         // Private wiki, only private headers
 275                         if ( $mode !== 'private' ) {
 276                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 277                                 return;
 278                         }
 279                 }
 280
 281                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 282                 $this->mCacheMode = $mode;
 283         }
 284
 285         /**
 286          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 287          * need to call this function. If there is a need, you can use
 288          * $this->setCacheMode('private')
 289          */
 290         public function setCachePrivate() {
 291                 wfDeprecated( __METHOD__, '1.17' );
 292                 $this->setCacheMode( 'private' );
 293         }
 294
 295         /**
 296          * Set directives (key/value pairs) for the Cache-Control header.
 297          * Boolean values will be formatted as such, by including or omitting
 298          * without an equals sign.
 299          *
 300          * Cache control values set here will only be used if the cache mode is not
 301          * private, see setCacheMode().
 302          *
 303          * @param $directives array
 304          */
 305         public function setCacheControl( $directives ) {
 306                 $this->mCacheControl = $directives + $this->mCacheControl;
 307         }
 308
 309         /**
 310          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 311          * may be cached for anons but may not be cached for logged-in users.
 312          *
 313          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 314          * given URL must either always or never call this function; if it sometimes does and
 315          * sometimes doesn't, stuff will break.
 316          *
 317          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 318          */
 319         public function setVaryCookie() {
 320                 wfDeprecated( __METHOD__, '1.17' );
 321                 $this->setCacheMode( 'anon-public-user-private' );
 322         }
 323
 324         /**
 325          * Create an instance of an output formatter by its name
 326          *
 327          * @param $format string
 328          *
 329          * @return ApiFormatBase
 330          */
 331         public function createPrinterByName( $format ) {
 332                 if ( !isset( $this->mFormats[$format] ) ) {
 333                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 334                 }
 335                 return new $this->mFormats[$format] ( $this, $format );
 336         }
 337
 338         /**
 339          * Execute api request. Any errors will be handled if the API was called by the remote client.
 340          */
 341         public function execute() {
 342                 $this->profileIn();
 343                 if ( $this->mInternalMode ) {
 344                         $this->executeAction();
 345                 } else {
 346                         $this->executeActionWithErrorHandling();
 347                 }
 348
 349                 $this->profileOut();
 350         }
 351
 352         /**
 353          * Execute an action, and in case of an error, erase whatever partial results
 354          * have been accumulated, and replace it with an error message and a help screen.
 355          */
 356         protected function executeActionWithErrorHandling() {
 357                 // Verify the CORS header before executing the action
 358                 if ( !$this->handleCORS() ) {
 359                         // handleCORS() has sent a 403, abort
 360                         return;
 361                 }
 362
 363                 // In case an error occurs during data output,
 364                 // clear the output buffer and print just the error information
 365                 ob_start();
 366
 367                 try {
 368                         $this->executeAction();
 369                 } catch ( Exception $e ) {
 370                         // Log it
 371                         if ( !( $e instanceof UsageException ) ) {
 372                                 wfDebugLog( 'exception', $e->getLogMessage() );
 373                         }
 374
 375                         // Handle any kind of exception by outputing properly formatted error message.
 376                         // If this fails, an unhandled exception should be thrown so that global error
 377                         // handler will process and log it.
 378
 379                         $errCode = $this->substituteResultWithError( $e );
 380
 381                         // Error results should not be cached
 382                         $this->setCacheMode( 'private' );
 383
 384                         $response = $this->getRequest()->response();
 385                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 386                         if ( $e->getCode() === 0 ) {
 387                                 $response->header( $headerStr );
 388                         } else {
 389                                 $response->header( $headerStr, true, $e->getCode() );
 390                         }
 391
 392                         // Reset and print just the error message
 393                         ob_clean();
 394
 395                         // If the error occured during printing, do a printer->profileOut()
 396                         $this->mPrinter->safeProfileOut();
 397                         $this->printResult( true );
 398                 }
 399
 400                 // Send cache headers after any code which might generate an error, to
 401                 // avoid sending public cache headers for errors.
 402                 $this->sendCacheHeaders();
 403
 404                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 405                         echo wfReportTime();
 406                 }
 407
 408                 ob_end_flush();
 409         }
 410
 411         /**
 412          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 413          *
 414          * If no origin parameter is present, nothing happens.
 415          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 416          * is set and false is returned.
 417          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 418          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 419          * headers are set.
 420          *
 421          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 422          */
 423         protected function handleCORS() {
 424                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 425                 $response = $this->getRequest()->response();
 426                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 427                 if ( $originParam === null ) {
 428                         // No origin parameter, nothing to do
 429                         return true;
 430                 }
 431                 // Origin: header is a space-separated list of origins, check all of them
 432                 $originHeader = isset( $_SERVER['HTTP_ORIGIN'] ) ? $_SERVER['HTTP_ORIGIN'] : '';
 433                 $origins = explode( ' ', $originHeader );
 434                 if ( !in_array( $originParam, $origins ) ) {
 435                         // origin parameter set but incorrect
 436                         // Send a 403 response
 437                         $message = HttpStatus::getMessage( 403 );
 438                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 439                         $response->header( 'Cache-Control: no-cache' );
 440                         echo "'origin' parameter does not match Origin header\n";
 441                         return false;
 442                 }
 443                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 444                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 445                         $response->header( 'Access-Control-Allow-Credentials: true' );
 446                         $this->getOutput()->addVaryHeader( 'Origin' );
 447                 }
 448                 return true;
 449         }
 450
 451         /**
 452          * Attempt to match an Origin header against a set of rules and a set of exceptions
 453          * @param $value string Origin header
 454          * @param $rules array Set of wildcard rules
 455          * @param $exceptions array Set of wildcard rules
 456          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 457          */
 458         protected static function matchOrigin( $value, $rules, $exceptions ) {
 459                 foreach ( $rules as $rule ) {
 460                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 461                                 // Rule matches, check exceptions
 462                                 foreach ( $exceptions as $exc ) {
 463                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 464                                                 return false;
 465                                         }
 466                                 }
 467                                 return true;
 468                         }
 469                 }
 470                 return false;
 471         }
 472
 473         /**
 474          * Helper function to convert wildcard string into a regex
 475          * '*' => '.*?'
 476          * '?' => '.'
 477          *
 478          * @param $wildcard string String with wildcards
 479          * @return string Regular expression
 480          */
 481         protected static function wildcardToRegex( $wildcard ) {
 482                 $wildcard = preg_quote( $wildcard, '/' );
 483                 $wildcard = str_replace(
 484                         array( '\*', '\?' ),
 485                         array( '.*?', '.' ),
 486                         $wildcard
 487                 );
 488                 return "/https?:\/\/$wildcard/";
 489         }
 490
 491         protected function sendCacheHeaders() {
 492                 global $wgUseXVO, $wgVaryOnXFP;
 493                 $response = $this->getRequest()->response();
 494                 $out = $this->getOutput();
 495
 496                 if ( $wgVaryOnXFP ) {
 497                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 498                 }
 499
 500                 if ( $this->mCacheMode == 'private' ) {
 501                         $response->header( 'Cache-Control: private' );
 502                         return;
 503                 }
 504
 505                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 506                         $out->addVaryHeader( 'Cookie' );
 507                         $response->header( $out->getVaryHeader() );
 508                         if ( $wgUseXVO ) {
 509                                 $response->header( $out->getXVO() );
 510                                 if ( $out->haveCacheVaryCookies() ) {
 511                                         // Logged in, mark this request private
 512                                         $response->header( 'Cache-Control: private' );
 513                                         return;
 514                                 }
 515                                 // Logged out, send normal public headers below
 516                         } elseif ( session_id() != '' ) {
 517                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 518                                 // Mark request private
 519                                 $response->header( 'Cache-Control: private' );
 520                                 return;
 521                         } // else no XVO and anonymous, send public headers below
 522                 }
 523
 524                 // Send public headers
 525                 $response->header( $out->getVaryHeader() );
 526                 if ( $wgUseXVO ) {
 527                         $response->header( $out->getXVO() );
 528                 }
 529
 530                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 531                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 532                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 533                 }
 534                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 535                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 536                 }
 537
 538                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 539                         // Public cache not requested
 540                         // Sending a Vary header in this case is harmless, and protects us
 541                         // against conditional calls of setCacheMaxAge().
 542                         $response->header( 'Cache-Control: private' );
 543                         return;
 544                 }
 545
 546                 $this->mCacheControl['public'] = true;
 547
 548                 // Send an Expires header
 549                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 550                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 551                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 552
 553                 // Construct the Cache-Control header
 554                 $ccHeader = '';
 555                 $separator = '';
 556                 foreach ( $this->mCacheControl as $name => $value ) {
 557                         if ( is_bool( $value ) ) {
 558                                 if ( $value ) {
 559                                         $ccHeader .= $separator . $name;
 560                                         $separator = ', ';
 561                                 }
 562                         } else {
 563                                 $ccHeader .= $separator . "$name=$value";
 564                                 $separator = ', ';
 565                         }
 566                 }
 567
 568                 $response->header( "Cache-Control: $ccHeader" );
 569         }
 570
 571         /**
 572          * Replace the result data with the information about an exception.
 573          * Returns the error code
 574          * @param $e Exception
 575          * @return string
 576          */
 577         protected function substituteResultWithError( $e ) {
 578                 global $wgShowHostnames;
 579
 580                 $result = $this->getResult();
 581                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 582                 if ( !isset ( $this->mPrinter ) ) {
 583                         // The printer has not been created yet. Try to manually get formatter value.
 584                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 585                         if ( !in_array( $value, $this->mFormatNames ) ) {
 586                                 $value = self::API_DEFAULT_FORMAT;
 587                         }
 588
 589                         $this->mPrinter = $this->createPrinterByName( $value );
 590                         if ( $this->mPrinter->getNeedsRawData() ) {
 591                                 $result->setRawMode();
 592                         }
 593                 }
 594
 595                 if ( $e instanceof UsageException ) {
 596                         // User entered incorrect parameters - print usage screen
 597                         $errMessage = $e->getMessageArray();
 598
 599                         // Only print the help message when this is for the developer, not runtime
 600                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 601                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 602                         }
 603
 604                 } else {
 605                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 606                         // Something is seriously wrong
 607                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 608                                 $info = 'Database query error';
 609                         } else {
 610                                 $info = "Exception Caught: {$e->getMessage()}";
 611                         }
 612
 613                         $errMessage = array(
 614                                 'code' => 'internal_api_error_' . get_class( $e ),
 615                                 'info' => $info,
 616                         );
 617                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 618                 }
 619
 620                 $result->reset();
 621                 $result->disableSizeCheck();
 622                 // Re-add the id
 623                 $requestid = $this->getParameter( 'requestid' );
 624                 if ( !is_null( $requestid ) ) {
 625                         $result->addValue( null, 'requestid', $requestid );
 626                 }
 627
 628                 if ( $wgShowHostnames ) {
 629                         // servedby is especially useful when debugging errors
 630                         $result->addValue( null, 'servedby', wfHostName() );
 631                 }
 632
 633                 $result->addValue( null, 'error', $errMessage );
 634
 635                 return $errMessage['code'];
 636         }
 637
 638         /**
 639          * Set up for the execution.
 640          * @return array
 641          */
 642         protected function setupExecuteAction() {
 643                 global $wgShowHostnames;
 644
 645                 // First add the id to the top element
 646                 $result = $this->getResult();
 647                 $requestid = $this->getParameter( 'requestid' );
 648                 if ( !is_null( $requestid ) ) {
 649                         $result->addValue( null, 'requestid', $requestid );
 650                 }
 651
 652                 if ( $wgShowHostnames ) {
 653                         $servedby = $this->getParameter( 'servedby' );
 654                         if ( $servedby ) {
 655                                 $result->addValue( null, 'servedby', wfHostName() );
 656                         }
 657                 }
 658
 659                 $params = $this->extractRequestParams();
 660
 661                 $this->mShowVersions = $params['version'];
 662                 $this->mAction = $params['action'];
 663
 664                 if ( !is_string( $this->mAction ) ) {
 665                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 666                 }
 667
 668                 return $params;
 669         }
 670
 671         /**
 672          * Set up the module for response
 673          * @return ApiBase The module that will handle this action
 674          */
 675         protected function setupModule() {
 676                 // Instantiate the module requested by the user
 677                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 678                 $this->mModule = $module;
 679
 680                 $moduleParams = $module->extractRequestParams();
 681
 682                 // Die if token required, but not provided (unless there is a gettoken parameter)
 683                 if ( isset( $moduleParams['gettoken'] ) ) {
 684                         $gettoken = $moduleParams['gettoken'];
 685                 } else {
 686                         $gettoken = false;
 687                 }
 688
 689                 $salt = $module->getTokenSalt();
 690                 if ( $salt !== false && !$gettoken ) {
 691                         if ( !isset( $moduleParams['token'] ) ) {
 692                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 693                         } else {
 694                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 695                                         $this->dieUsageMsg( 'sessionfailure' );
 696                                 }
 697                         }
 698                 }
 699                 return $module;
 700         }
 701
 702         /**
 703          * Check the max lag if necessary
 704          * @param $module ApiBase object: Api module being used
 705          * @param $params Array an array containing the request parameters.
 706          * @return boolean True on success, false should exit immediately
 707          */
 708         protected function checkMaxLag( $module, $params ) {
 709                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 710                         // Check for maxlag
 711                         global $wgShowHostnames;
 712                         $maxLag = $params['maxlag'];
 713                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 714                         if ( $lag > $maxLag ) {
 715                                 $response = $this->getRequest()->response();
 716
 717                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 718                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 719
 720                                 if ( $wgShowHostnames ) {
 721                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 722                                 } else {
 723                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 724                                 }
 725                                 return false;
 726                         }
 727                 }
 728                 return true;
 729         }
 730
 731         /**
 732          * Check for sufficient permissions to execute
 733          * @param $module ApiBase An Api module
 734          */
 735         protected function checkExecutePermissions( $module ) {
 736                 $user = $this->getUser();
 737                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 738                         !$user->isAllowed( 'read' ) )
 739                 {
 740                         $this->dieUsageMsg( 'readrequired' );
 741                 }
 742                 if ( $module->isWriteMode() ) {
 743                         if ( !$this->mEnableWrite ) {
 744                                 $this->dieUsageMsg( 'writedisabled' );
 745                         }
 746                         if ( !$user->isAllowed( 'writeapi' ) ) {
 747                                 $this->dieUsageMsg( 'writerequired' );
 748                         }
 749                         if ( wfReadOnly() ) {
 750                                 $this->dieReadOnly();
 751                         }
 752                 }
 753         }
 754
 755         /**
 756          * Check POST for external response and setup result printer
 757          * @param $module ApiBase An Api module
 758          * @param $params Array an array with the request parameters
 759          */
 760         protected function setupExternalResponse( $module, $params ) {
 761                 // Ignore mustBePosted() for internal calls
 762                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 763                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 764                 }
 765
 766                 // See if custom printer is used
 767                 $this->mPrinter = $module->getCustomPrinter();
 768                 if ( is_null( $this->mPrinter ) ) {
 769                         // Create an appropriate printer
 770                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 771                 }
 772
 773                 if ( $this->mPrinter->getNeedsRawData() ) {
 774                         $this->getResult()->setRawMode();
 775                 }
 776         }
 777
 778         /**
 779          * Execute the actual module, without any error handling
 780          */
 781         protected function executeAction() {
 782                 $params = $this->setupExecuteAction();
 783                 $module = $this->setupModule();
 784
 785                 $this->checkExecutePermissions( $module );
 786
 787                 if ( !$this->checkMaxLag( $module, $params ) ) {
 788                         return;
 789                 }
 790
 791                 if ( !$this->mInternalMode ) {
 792                         $this->setupExternalResponse( $module, $params );
 793                 }
 794
 795                 // Execute
 796                 $module->profileIn();
 797                 $module->execute();
 798                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 799                 $module->profileOut();
 800
 801                 if ( !$this->mInternalMode ) {
 802                         //append Debug information
 803                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 804
 805                         // Print result data
 806                         $this->printResult( false );
 807                 }
 808         }
 809
 810         /**
 811          * Print results using the current printer
 812          *
 813          * @param $isError bool
 814          */
 815         protected function printResult( $isError ) {
 816                 $this->getResult()->cleanUpUTF8();
 817                 $printer = $this->mPrinter;
 818                 $printer->profileIn();
 819
 820                 /**
 821                  * If the help message is requested in the default (xmlfm) format,
 822                  * tell the printer not to escape ampersands so that our links do
 823                  * not break.
 824                  */
 825                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 826                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 827
 828                 $printer->initPrinter( $isError );
 829
 830                 $printer->execute();
 831                 $printer->closePrinter();
 832                 $printer->profileOut();
 833         }
 834
 835         /**
 836          * @return bool
 837          */
 838         public function isReadMode() {
 839                 return false;
 840         }
 841
 842         /**
 843          * See ApiBase for description.
 844          *
 845          * @return array
 846          */
 847         public function getAllowedParams() {
 848                 return array(
 849                         'format' => array(
 850                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 851                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 852                         ),
 853                         'action' => array(
 854                                 ApiBase::PARAM_DFLT => 'help',
 855                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 856                         ),
 857                         'version' => false,
 858                         'maxlag'  => array(
 859                                 ApiBase::PARAM_TYPE => 'integer'
 860                         ),
 861                         'smaxage' => array(
 862                                 ApiBase::PARAM_TYPE => 'integer',
 863                                 ApiBase::PARAM_DFLT => 0
 864                         ),
 865                         'maxage' => array(
 866                                 ApiBase::PARAM_TYPE => 'integer',
 867                                 ApiBase::PARAM_DFLT => 0
 868                         ),
 869                         'requestid' => null,
 870                         'servedby'  => false,
 871                         'origin' => null,
 872                 );
 873         }
 874
 875         /**
 876          * See ApiBase for description.
 877          *
 878          * @return array
 879          */
 880         public function getParamDescription() {
 881                 return array(
 882                         'format' => 'The format of the output',
 883                         'action' => 'What action you would like to perform. See below for module help',
 884                         'version' => 'When showing help, include version for each module',
 885                         'maxlag' => array(
 886                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 887                                 'To save actions causing any more site replication lag, this parameter can make the client',
 888                                 'wait until the replication lag is less than the specified value.',
 889                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 890                                 '"Waiting for $host: $lag seconds lagged\n".',
 891                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 892                         ),
 893                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 894                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 895                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 896                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 897                         'origin' => array(
 898                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
 899                                 'This must match one of the origins in the Origin: header exactly, so it has to be set to something like http://en.wikipedia.org or https://meta.wikimedia.org .',
 900                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
 901                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
 902                         ),
 903                 );
 904         }
 905
 906         /**
 907          * See ApiBase for description.
 908          *
 909          * @return array
 910          */
 911         public function getDescription() {
 912                 return array(
 913                         '',
 914                         '',
 915                         '**********************************************************************************************************',
 916                         '**                                                                                                      **',
 917                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 918                         '**                                                                                                      **',
 919                         '**                                     Documentation and Examples:                                      **',
 920                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 921                         '**                                                                                                      **',
 922                         '**********************************************************************************************************',
 923                         '',
 924                         'Status:                All features shown on this page should be working, but the API',
 925                         '                       is still in active development, and may change at any time.',
 926                         '                       Make sure to monitor our mailing list for any updates',
 927                         '',
 928                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 929                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 930                         '                       header and the error code sent back will be set to the same value',
 931                         '',
 932                         '                       In the case of an invalid action being passed, these will have a value',
 933                         '                       of "unknown_action"',
 934                         '',
 935                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 936                         '',
 937                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 938                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 939                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 940                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 941                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 942                         '',
 943                         '',
 944                         '',
 945                         '',
 946                         '',
 947                 );
 948         }
 949
 950         /**
 951          * @return array
 952          */
 953         public function getPossibleErrors() {
 954                 return array_merge( parent::getPossibleErrors(), array(
 955                         array( 'readonlytext' ),
 956                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 957                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 958                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 959                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 960                 ) );
 961         }
 962
 963         /**
 964          * Returns an array of strings with credits for the API
 965          * @return array
 966          */
 967         protected function getCredits() {
 968                 return array(
 969                         'API developers:',
 970                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
 971                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 972                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 973                         '    Sam Reed - sam @ reedyboy . net',
 974                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
 975                         '',
 976                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 977                         'or file a bug report at https://bugzilla.wikimedia.org/'
 978                 );
 979         }
 980
 981         /**
 982          * Sets whether the pretty-printer should format *bold* and $italics$
 983          *
 984          * @param $help bool
 985          */
 986         public function setHelp( $help = true ) {
 987                 $this->mPrinter->setHelp( $help );
 988         }
 989
 990         /**
 991          * Override the parent to generate help messages for all available modules.
 992          *
 993          * @return string
 994          */
 995         public function makeHelpMsg() {
 996                 global $wgMemc, $wgAPICacheHelpTimeout;
 997                 $this->setHelp();
 998                 // Get help text from cache if present
 999                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1000                         SpecialVersion::getVersion( 'nodb' ) .
1001                         $this->getShowVersions() );
1002                 if ( $wgAPICacheHelpTimeout > 0 ) {
1003                         $cached = $wgMemc->get( $key );
1004                         if ( $cached ) {
1005                                 return $cached;
1006                         }
1007                 }
1008                 $retval = $this->reallyMakeHelpMsg();
1009                 if ( $wgAPICacheHelpTimeout > 0 ) {
1010                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1011                 }
1012                 return $retval;
1013         }
1014
1015         /**
1016          * @return mixed|string
1017          */
1018         public function reallyMakeHelpMsg() {
1019                 $this->setHelp();
1020
1021                 // Use parent to make default message for the main module
1022                 $msg = parent::makeHelpMsg();
1023
1024                 $astriks = str_repeat( '*** ', 14 );
1025                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1026                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1027                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1028                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1029                         $msg2 = $module->makeHelpMsg();
1030                         if ( $msg2 !== false ) {
1031                                 $msg .= $msg2;
1032                         }
1033                         $msg .= "\n";
1034                 }
1035
1036                 $msg .= "\n$astriks Permissions $astriks\n\n";
1037                 foreach ( self::$mRights as $right => $rightMsg ) {
1038                         $groups = User::getGroupsWithPermission( $right );
1039                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
1040                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1041
1042                 }
1043
1044                 $msg .= "\n$astriks Formats  $astriks\n\n";
1045                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1046                         $module = $this->createPrinterByName( $formatName );
1047                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1048                         $msg2 = $module->makeHelpMsg();
1049                         if ( $msg2 !== false ) {
1050                                 $msg .= $msg2;
1051                         }
1052                         $msg .= "\n";
1053                 }
1054
1055                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1056
1057                 return $msg;
1058         }
1059
1060         /**
1061          * @param $module ApiBase
1062          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1063          * @return string
1064          */
1065         public static function makeHelpMsgHeader( $module, $paramName ) {
1066                 $modulePrefix = $module->getModulePrefix();
1067                 if ( strval( $modulePrefix ) !== '' ) {
1068                         $modulePrefix = "($modulePrefix) ";
1069                 }
1070
1071                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1072         }
1073
1074         private $mCanApiHighLimits = null;
1075
1076         /**
1077          * Check whether the current user is allowed to use high limits
1078          * @return bool
1079          */
1080         public function canApiHighLimits() {
1081                 if ( !isset( $this->mCanApiHighLimits ) ) {
1082                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1083                 }
1084
1085                 return $this->mCanApiHighLimits;
1086         }
1087
1088         /**
1089          * Check whether the user wants us to show version information in the API help
1090          * @return bool
1091          */
1092         public function getShowVersions() {
1093                 return $this->mShowVersions;
1094         }
1095
1096         /**
1097          * Returns the version information of this file, plus it includes
1098          * the versions for all files that are not callable proper API modules
1099          *
1100          * @return array
1101          */
1102         public function getVersion() {
1103                 $vers = array();
1104                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1105                 $vers[] = __CLASS__ . ': $Id$';
1106                 $vers[] = ApiBase::getBaseVersion();
1107                 $vers[] = ApiFormatBase::getBaseVersion();
1108                 $vers[] = ApiQueryBase::getBaseVersion();
1109                 return $vers;
1110         }
1111
1112         /**
1113          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1114          * classes who wish to add their own modules to their lexicon or override the
1115          * behavior of inherent ones.
1116          *
1117          * @param $mdlName String The identifier for this module.
1118          * @param $mdlClass String The class where this module is implemented.
1119          */
1120         protected function addModule( $mdlName, $mdlClass ) {
1121                 $this->mModules[$mdlName] = $mdlClass;
1122         }
1123
1124         /**
1125          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1126          * classes who wish to add to or modify current formatters.
1127          *
1128          * @param $fmtName string The identifier for this format.
1129          * @param $fmtClass ApiFormatBase The class implementing this format.
1130          */
1131         protected function addFormat( $fmtName, $fmtClass ) {
1132                 $this->mFormats[$fmtName] = $fmtClass;
1133         }
1134
1135         /**
1136          * Get the array mapping module names to class names
1137          * @return array
1138          */
1139         function getModules() {
1140                 return $this->mModules;
1141         }
1142
1143         /**
1144          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1145          *
1146          * @since 1.18
1147          * @return array
1148          */
1149         public function getFormats() {
1150                 return $this->mFormats;
1151         }
1152 }
1153
1154 /**
1155  * This exception will be thrown when dieUsage is called to stop module execution.
1156  * The exception handling code will print a help screen explaining how this API may be used.
1157  *
1158  * @ingroup API
1159  */
1160 class UsageException extends MWException {
1161
1162         private $mCodestr;
1163
1164         /**
1165          * @var null|array
1166          */
1167         private $mExtraData;
1168
1169         /**
1170          * @param $message string
1171          * @param $codestr string
1172          * @param $code int
1173          * @param $extradata array|null
1174          */
1175         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1176                 parent::__construct( $message, $code );
1177                 $this->mCodestr = $codestr;
1178                 $this->mExtraData = $extradata;
1179         }
1180
1181         /**
1182          * @return string
1183          */
1184         public function getCodeString() {
1185                 return $this->mCodestr;
1186         }
1187
1188         /**
1189          * @return array
1190          */
1191         public function getMessageArray() {
1192                 $result = array(
1193                         'code' => $this->mCodestr,
1194                         'info' => $this->getMessage()
1195                 );
1196                 if ( is_array( $this->mExtraData ) ) {
1197                         $result = array_merge( $result, $this->mExtraData );
1198                 }
1199                 return $result;
1200         }
1201
1202         /**
1203          * @return string
1204          */
1205         public function __toString() {
1206                 return "{$this->getCodeString()}: {$this->getMessage()}";
1207         }
1208 }