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                 'none' => 'ApiFormatNone',
 108         );
 109
 110         /**
 111          * List of user roles that are specifically relevant to the API.
 112          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 113          *                           'params' => array ( $someVarToSubst ) ),
 114          *                          );
 115          */
 116         private static $mRights = array(
 117                 'writeapi' => array(
 118                         'msg' => 'Use of the write API',
 119                         'params' => array()
 120                 ),
 121                 'apihighlimits' => array(
 122                         '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.',
 123                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 124                 )
 125         );
 126
 127         /**
 128          * @var ApiFormatBase
 129          */
 130         private $mPrinter;
 131
 132         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 133         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 134         private $mInternalMode, $mSquidMaxage, $mModule;
 135
 136         private $mCacheMode = 'private';
 137         private $mCacheControl = array();
 138
 139         /**
 140          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 141          *
 142          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 143          * @param $enableWrite bool should be set to true if the api may modify data
 144          */
 145         public function __construct( $context = null, $enableWrite = false ) {
 146                 if ( $context === null ) {
 147                         $context = RequestContext::getMain();
 148                 } elseif ( $context instanceof WebRequest ) {
 149                         // BC for pre-1.19
 150                         $request = $context;
 151                         $context = RequestContext::getMain();
 152                 }
 153                 // We set a derivative context so we can change stuff later
 154                 $this->setContext( new DerivativeContext( $context ) );
 155
 156                 if ( isset( $request ) ) {
 157                         $this->getContext()->setRequest( $request );
 158                 }
 159
 160                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 161
 162                 // Special handling for the main module: $parent === $this
 163                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 164
 165                 if ( !$this->mInternalMode ) {
 166                         // Impose module restrictions.
 167                         // If the current user cannot read,
 168                         // Remove all modules other than login
 169                         global $wgUser;
 170
 171                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 172                                 // JSON callback allows cross-site reads.
 173                                 // For safety, strip user credentials.
 174                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 175                                 $wgUser = new User();
 176                                 $this->getContext()->setUser( $wgUser );
 177                         }
 178                 }
 179
 180                 global $wgAPIModules; // extension modules
 181                 $this->mModules = $wgAPIModules + self::$Modules;
 182
 183                 $this->mModuleNames = array_keys( $this->mModules );
 184                 $this->mFormats = self::$Formats;
 185                 $this->mFormatNames = array_keys( $this->mFormats );
 186
 187                 $this->mResult = new ApiResult( $this );
 188                 $this->mShowVersions = false;
 189                 $this->mEnableWrite = $enableWrite;
 190
 191                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 192                 $this->mCommit = false;
 193         }
 194
 195         /**
 196          * Return true if the API was started by other PHP code using FauxRequest
 197          * @return bool
 198          */
 199         public function isInternalMode() {
 200                 return $this->mInternalMode;
 201         }
 202
 203         /**
 204          * Get the ApiResult object associated with current request
 205          *
 206          * @return ApiResult
 207          */
 208         public function getResult() {
 209                 return $this->mResult;
 210         }
 211
 212         /**
 213          * Get the API module object. Only works after executeAction()
 214          *
 215          * @return ApiBase
 216          */
 217         public function getModule() {
 218                 return $this->mModule;
 219         }
 220
 221         /**
 222          * Get the result formatter object. Only works after setupExecuteAction()
 223          *
 224          * @return ApiFormatBase
 225          */
 226         public function getPrinter() {
 227                 return $this->mPrinter;
 228         }
 229
 230         /**
 231          * Set how long the response should be cached.
 232          *
 233          * @param $maxage
 234          */
 235         public function setCacheMaxAge( $maxage ) {
 236                 $this->setCacheControl( array(
 237                         'max-age' => $maxage,
 238                         's-maxage' => $maxage
 239                 ) );
 240         }
 241
 242         /**
 243          * Set the type of caching headers which will be sent.
 244          *
 245          * @param $mode String One of:
 246          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 247          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 248          *         not provided by any of these means, the object will be private.
 249          *    - 'private':    Cache this object only in private client-side caches.
 250          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 251          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 252          *         set consistently for a given URL, it cannot be set differently depending on
 253          *         things like the contents of the database, or whether the user is logged in.
 254          *
 255          *  If the wiki does not allow anonymous users to read it, the mode set here
 256          *  will be ignored, and private caching headers will always be sent. In other words,
 257          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 258          *  view.
 259          *
 260          *  For user-dependent data, the private mode should generally be used. The
 261          *  anon-public-user-private mode should only be used where there is a particularly
 262          *  good performance reason for caching the anonymous response, but where the
 263          *  response to logged-in users may differ, or may contain private data.
 264          *
 265          *  If this function is never called, then the default will be the private mode.
 266          */
 267         public function setCacheMode( $mode ) {
 268                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 269                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 270                         // Ignore for forwards-compatibility
 271                         return;
 272                 }
 273
 274                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 275                         // Private wiki, only private headers
 276                         if ( $mode !== 'private' ) {
 277                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 278                                 return;
 279                         }
 280                 }
 281
 282                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 283                 $this->mCacheMode = $mode;
 284         }
 285
 286         /**
 287          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 288          * need to call this function. If there is a need, you can use
 289          * $this->setCacheMode('private')
 290          */
 291         public function setCachePrivate() {
 292                 wfDeprecated( __METHOD__, '1.17' );
 293                 $this->setCacheMode( 'private' );
 294         }
 295
 296         /**
 297          * Set directives (key/value pairs) for the Cache-Control header.
 298          * Boolean values will be formatted as such, by including or omitting
 299          * without an equals sign.
 300          *
 301          * Cache control values set here will only be used if the cache mode is not
 302          * private, see setCacheMode().
 303          *
 304          * @param $directives array
 305          */
 306         public function setCacheControl( $directives ) {
 307                 $this->mCacheControl = $directives + $this->mCacheControl;
 308         }
 309
 310         /**
 311          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 312          * may be cached for anons but may not be cached for logged-in users.
 313          *
 314          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 315          * given URL must either always or never call this function; if it sometimes does and
 316          * sometimes doesn't, stuff will break.
 317          *
 318          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 319          */
 320         public function setVaryCookie() {
 321                 wfDeprecated( __METHOD__, '1.17' );
 322                 $this->setCacheMode( 'anon-public-user-private' );
 323         }
 324
 325         /**
 326          * Create an instance of an output formatter by its name
 327          *
 328          * @param $format string
 329          *
 330          * @return ApiFormatBase
 331          */
 332         public function createPrinterByName( $format ) {
 333                 if ( !isset( $this->mFormats[$format] ) ) {
 334                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 335                 }
 336                 return new $this->mFormats[$format] ( $this, $format );
 337         }
 338
 339         /**
 340          * Execute api request. Any errors will be handled if the API was called by the remote client.
 341          */
 342         public function execute() {
 343                 $this->profileIn();
 344                 if ( $this->mInternalMode ) {
 345                         $this->executeAction();
 346                 } else {
 347                         $this->executeActionWithErrorHandling();
 348                 }
 349
 350                 $this->profileOut();
 351         }
 352
 353         /**
 354          * Execute an action, and in case of an error, erase whatever partial results
 355          * have been accumulated, and replace it with an error message and a help screen.
 356          */
 357         protected function executeActionWithErrorHandling() {
 358                 // Verify the CORS header before executing the action
 359                 if ( !$this->handleCORS() ) {
 360                         // handleCORS() has sent a 403, abort
 361                         return;
 362                 }
 363
 364                 // In case an error occurs during data output,
 365                 // clear the output buffer and print just the error information
 366                 ob_start();
 367
 368                 try {
 369                         $this->executeAction();
 370                 } catch ( Exception $e ) {
 371                         // Log it
 372                         if ( !( $e instanceof UsageException ) ) {
 373                                 wfDebugLog( 'exception', $e->getLogMessage() );
 374                         }
 375
 376                         // Handle any kind of exception by outputing properly formatted error message.
 377                         // If this fails, an unhandled exception should be thrown so that global error
 378                         // handler will process and log it.
 379
 380                         $errCode = $this->substituteResultWithError( $e );
 381
 382                         // Error results should not be cached
 383                         $this->setCacheMode( 'private' );
 384
 385                         $response = $this->getRequest()->response();
 386                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 387                         if ( $e->getCode() === 0 ) {
 388                                 $response->header( $headerStr );
 389                         } else {
 390                                 $response->header( $headerStr, true, $e->getCode() );
 391                         }
 392
 393                         // Reset and print just the error message
 394                         ob_clean();
 395
 396                         // If the error occured during printing, do a printer->profileOut()
 397                         $this->mPrinter->safeProfileOut();
 398                         $this->printResult( true );
 399                 }
 400
 401                 // Send cache headers after any code which might generate an error, to
 402                 // avoid sending public cache headers for errors.
 403                 $this->sendCacheHeaders();
 404
 405                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 406                         echo wfReportTime();
 407                 }
 408
 409                 ob_end_flush();
 410         }
 411
 412         /**
 413          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 414          *
 415          * If no origin parameter is present, nothing happens.
 416          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 417          * is set and false is returned.
 418          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 419          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 420          * headers are set.
 421          *
 422          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 423          */
 424         protected function handleCORS() {
 425                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 426                 $response = $this->getRequest()->response();
 427                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 428                 if ( $originParam === null ) {
 429                         // No origin parameter, nothing to do
 430                         return true;
 431                 }
 432                 // Origin: header is a space-separated list of origins, check all of them
 433                 $originHeader = isset( $_SERVER['HTTP_ORIGIN'] ) ? $_SERVER['HTTP_ORIGIN'] : '';
 434                 $origins = explode( ' ', $originHeader );
 435                 if ( !in_array( $originParam, $origins ) ) {
 436                         // origin parameter set but incorrect
 437                         // Send a 403 response
 438                         $message = HttpStatus::getMessage( 403 );
 439                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 440                         $response->header( 'Cache-Control: no-cache' );
 441                         echo "'origin' parameter does not match Origin header\n";
 442                         return false;
 443                 }
 444                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 445                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 446                         $response->header( 'Access-Control-Allow-Credentials: true' );
 447                         $this->getOutput()->addVaryHeader( 'Origin' );
 448                 }
 449                 return true;
 450         }
 451
 452         /**
 453          * Attempt to match an Origin header against a set of rules and a set of exceptions
 454          * @param $value string Origin header
 455          * @param $rules array Set of wildcard rules
 456          * @param $exceptions array Set of wildcard rules
 457          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 458          */
 459         protected static function matchOrigin( $value, $rules, $exceptions ) {
 460                 foreach ( $rules as $rule ) {
 461                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 462                                 // Rule matches, check exceptions
 463                                 foreach ( $exceptions as $exc ) {
 464                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 465                                                 return false;
 466                                         }
 467                                 }
 468                                 return true;
 469                         }
 470                 }
 471                 return false;
 472         }
 473
 474         /**
 475          * Helper function to convert wildcard string into a regex
 476          * '*' => '.*?'
 477          * '?' => '.'
 478          *
 479          * @param $wildcard string String with wildcards
 480          * @return string Regular expression
 481          */
 482         protected static function wildcardToRegex( $wildcard ) {
 483                 $wildcard = preg_quote( $wildcard, '/' );
 484                 $wildcard = str_replace(
 485                         array( '\*', '\?' ),
 486                         array( '.*?', '.' ),
 487                         $wildcard
 488                 );
 489                 return "/https?:\/\/$wildcard/";
 490         }
 491
 492         protected function sendCacheHeaders() {
 493                 global $wgUseXVO, $wgVaryOnXFP;
 494                 $response = $this->getRequest()->response();
 495                 $out = $this->getOutput();
 496
 497                 if ( $wgVaryOnXFP ) {
 498                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 499                 }
 500
 501                 if ( $this->mCacheMode == 'private' ) {
 502                         $response->header( 'Cache-Control: private' );
 503                         return;
 504                 }
 505
 506                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 507                         $out->addVaryHeader( 'Cookie' );
 508                         $response->header( $out->getVaryHeader() );
 509                         if ( $wgUseXVO ) {
 510                                 $response->header( $out->getXVO() );
 511                                 if ( $out->haveCacheVaryCookies() ) {
 512                                         // Logged in, mark this request private
 513                                         $response->header( 'Cache-Control: private' );
 514                                         return;
 515                                 }
 516                                 // Logged out, send normal public headers below
 517                         } elseif ( session_id() != '' ) {
 518                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 519                                 // Mark request private
 520                                 $response->header( 'Cache-Control: private' );
 521                                 return;
 522                         } // else no XVO and anonymous, send public headers below
 523                 }
 524
 525                 // Send public headers
 526                 $response->header( $out->getVaryHeader() );
 527                 if ( $wgUseXVO ) {
 528                         $response->header( $out->getXVO() );
 529                 }
 530
 531                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 532                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 533                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 534                 }
 535                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 536                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 537                 }
 538
 539                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 540                         // Public cache not requested
 541                         // Sending a Vary header in this case is harmless, and protects us
 542                         // against conditional calls of setCacheMaxAge().
 543                         $response->header( 'Cache-Control: private' );
 544                         return;
 545                 }
 546
 547                 $this->mCacheControl['public'] = true;
 548
 549                 // Send an Expires header
 550                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 551                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 552                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 553
 554                 // Construct the Cache-Control header
 555                 $ccHeader = '';
 556                 $separator = '';
 557                 foreach ( $this->mCacheControl as $name => $value ) {
 558                         if ( is_bool( $value ) ) {
 559                                 if ( $value ) {
 560                                         $ccHeader .= $separator . $name;
 561                                         $separator = ', ';
 562                                 }
 563                         } else {
 564                                 $ccHeader .= $separator . "$name=$value";
 565                                 $separator = ', ';
 566                         }
 567                 }
 568
 569                 $response->header( "Cache-Control: $ccHeader" );
 570         }
 571
 572         /**
 573          * Replace the result data with the information about an exception.
 574          * Returns the error code
 575          * @param $e Exception
 576          * @return string
 577          */
 578         protected function substituteResultWithError( $e ) {
 579                 global $wgShowHostnames;
 580
 581                 $result = $this->getResult();
 582                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 583                 if ( !isset ( $this->mPrinter ) ) {
 584                         // The printer has not been created yet. Try to manually get formatter value.
 585                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 586                         if ( !in_array( $value, $this->mFormatNames ) ) {
 587                                 $value = self::API_DEFAULT_FORMAT;
 588                         }
 589
 590                         $this->mPrinter = $this->createPrinterByName( $value );
 591                         if ( $this->mPrinter->getNeedsRawData() ) {
 592                                 $result->setRawMode();
 593                         }
 594                 }
 595
 596                 if ( $e instanceof UsageException ) {
 597                         // User entered incorrect parameters - print usage screen
 598                         $errMessage = $e->getMessageArray();
 599
 600                         // Only print the help message when this is for the developer, not runtime
 601                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 602                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 603                         }
 604
 605                 } else {
 606                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 607                         // Something is seriously wrong
 608                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 609                                 $info = 'Database query error';
 610                         } else {
 611                                 $info = "Exception Caught: {$e->getMessage()}";
 612                         }
 613
 614                         $errMessage = array(
 615                                 'code' => 'internal_api_error_' . get_class( $e ),
 616                                 'info' => $info,
 617                         );
 618                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 619                 }
 620
 621                 $result->reset();
 622                 $result->disableSizeCheck();
 623                 // Re-add the id
 624                 $requestid = $this->getParameter( 'requestid' );
 625                 if ( !is_null( $requestid ) ) {
 626                         $result->addValue( null, 'requestid', $requestid );
 627                 }
 628
 629                 if ( $wgShowHostnames ) {
 630                         // servedby is especially useful when debugging errors
 631                         $result->addValue( null, 'servedby', wfHostName() );
 632                 }
 633
 634                 $result->addValue( null, 'error', $errMessage );
 635
 636                 return $errMessage['code'];
 637         }
 638
 639         /**
 640          * Set up for the execution.
 641          * @return array
 642          */
 643         protected function setupExecuteAction() {
 644                 global $wgShowHostnames;
 645
 646                 // First add the id to the top element
 647                 $result = $this->getResult();
 648                 $requestid = $this->getParameter( 'requestid' );
 649                 if ( !is_null( $requestid ) ) {
 650                         $result->addValue( null, 'requestid', $requestid );
 651                 }
 652
 653                 if ( $wgShowHostnames ) {
 654                         $servedby = $this->getParameter( 'servedby' );
 655                         if ( $servedby ) {
 656                                 $result->addValue( null, 'servedby', wfHostName() );
 657                         }
 658                 }
 659
 660                 $params = $this->extractRequestParams();
 661
 662                 $this->mShowVersions = $params['version'];
 663                 $this->mAction = $params['action'];
 664
 665                 if ( !is_string( $this->mAction ) ) {
 666                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 667                 }
 668
 669                 return $params;
 670         }
 671
 672         /**
 673          * Set up the module for response
 674          * @return ApiBase The module that will handle this action
 675          */
 676         protected function setupModule() {
 677                 // Instantiate the module requested by the user
 678                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 679                 $this->mModule = $module;
 680
 681                 $moduleParams = $module->extractRequestParams();
 682
 683                 // Die if token required, but not provided (unless there is a gettoken parameter)
 684                 if ( isset( $moduleParams['gettoken'] ) ) {
 685                         $gettoken = $moduleParams['gettoken'];
 686                 } else {
 687                         $gettoken = false;
 688                 }
 689
 690                 $salt = $module->getTokenSalt();
 691                 if ( $salt !== false && !$gettoken ) {
 692                         if ( !isset( $moduleParams['token'] ) ) {
 693                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 694                         } else {
 695                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 696                                         $this->dieUsageMsg( 'sessionfailure' );
 697                                 }
 698                         }
 699                 }
 700                 return $module;
 701         }
 702
 703         /**
 704          * Check the max lag if necessary
 705          * @param $module ApiBase object: Api module being used
 706          * @param $params Array an array containing the request parameters.
 707          * @return boolean True on success, false should exit immediately
 708          */
 709         protected function checkMaxLag( $module, $params ) {
 710                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 711                         // Check for maxlag
 712                         global $wgShowHostnames;
 713                         $maxLag = $params['maxlag'];
 714                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 715                         if ( $lag > $maxLag ) {
 716                                 $response = $this->getRequest()->response();
 717
 718                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 719                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 720
 721                                 if ( $wgShowHostnames ) {
 722                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 723                                 } else {
 724                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 725                                 }
 726                                 return false;
 727                         }
 728                 }
 729                 return true;
 730         }
 731
 732         /**
 733          * Check for sufficient permissions to execute
 734          * @param $module ApiBase An Api module
 735          */
 736         protected function checkExecutePermissions( $module ) {
 737                 $user = $this->getUser();
 738                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 739                         !$user->isAllowed( 'read' ) )
 740                 {
 741                         $this->dieUsageMsg( 'readrequired' );
 742                 }
 743                 if ( $module->isWriteMode() ) {
 744                         if ( !$this->mEnableWrite ) {
 745                                 $this->dieUsageMsg( 'writedisabled' );
 746                         }
 747                         if ( !$user->isAllowed( 'writeapi' ) ) {
 748                                 $this->dieUsageMsg( 'writerequired' );
 749                         }
 750                         if ( wfReadOnly() ) {
 751                                 $this->dieReadOnly();
 752                         }
 753                 }
 754         }
 755
 756         /**
 757          * Check POST for external response and setup result printer
 758          * @param $module ApiBase An Api module
 759          * @param $params Array an array with the request parameters
 760          */
 761         protected function setupExternalResponse( $module, $params ) {
 762                 // Ignore mustBePosted() for internal calls
 763                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 764                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 765                 }
 766
 767                 // See if custom printer is used
 768                 $this->mPrinter = $module->getCustomPrinter();
 769                 if ( is_null( $this->mPrinter ) ) {
 770                         // Create an appropriate printer
 771                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 772                 }
 773
 774                 if ( $this->mPrinter->getNeedsRawData() ) {
 775                         $this->getResult()->setRawMode();
 776                 }
 777         }
 778
 779         /**
 780          * Execute the actual module, without any error handling
 781          */
 782         protected function executeAction() {
 783                 $params = $this->setupExecuteAction();
 784                 $module = $this->setupModule();
 785
 786                 $this->checkExecutePermissions( $module );
 787
 788                 if ( !$this->checkMaxLag( $module, $params ) ) {
 789                         return;
 790                 }
 791
 792                 if ( !$this->mInternalMode ) {
 793                         $this->setupExternalResponse( $module, $params );
 794                 }
 795
 796                 // Execute
 797                 $module->profileIn();
 798                 $module->execute();
 799                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 800                 $module->profileOut();
 801
 802                 if ( !$this->mInternalMode ) {
 803                         //append Debug information
 804                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 805
 806                         // Print result data
 807                         $this->printResult( false );
 808                 }
 809         }
 810
 811         /**
 812          * Print results using the current printer
 813          *
 814          * @param $isError bool
 815          */
 816         protected function printResult( $isError ) {
 817                 $this->getResult()->cleanUpUTF8();
 818                 $printer = $this->mPrinter;
 819                 $printer->profileIn();
 820
 821                 /**
 822                  * If the help message is requested in the default (xmlfm) format,
 823                  * tell the printer not to escape ampersands so that our links do
 824                  * not break.
 825                  */
 826                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 827                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 828
 829                 $printer->initPrinter( $isError );
 830
 831                 $printer->execute();
 832                 $printer->closePrinter();
 833                 $printer->profileOut();
 834         }
 835
 836         /**
 837          * @return bool
 838          */
 839         public function isReadMode() {
 840                 return false;
 841         }
 842
 843         /**
 844          * See ApiBase for description.
 845          *
 846          * @return array
 847          */
 848         public function getAllowedParams() {
 849                 return array(
 850                         'format' => array(
 851                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 852                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 853                         ),
 854                         'action' => array(
 855                                 ApiBase::PARAM_DFLT => 'help',
 856                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 857                         ),
 858                         'version' => false,
 859                         'maxlag'  => array(
 860                                 ApiBase::PARAM_TYPE => 'integer'
 861                         ),
 862                         'smaxage' => array(
 863                                 ApiBase::PARAM_TYPE => 'integer',
 864                                 ApiBase::PARAM_DFLT => 0
 865                         ),
 866                         'maxage' => array(
 867                                 ApiBase::PARAM_TYPE => 'integer',
 868                                 ApiBase::PARAM_DFLT => 0
 869                         ),
 870                         'requestid' => null,
 871                         'servedby'  => false,
 872                         'origin' => null,
 873                 );
 874         }
 875
 876         /**
 877          * See ApiBase for description.
 878          *
 879          * @return array
 880          */
 881         public function getParamDescription() {
 882                 return array(
 883                         'format' => 'The format of the output',
 884                         'action' => 'What action you would like to perform. See below for module help',
 885                         'version' => 'When showing help, include version for each module',
 886                         'maxlag' => array(
 887                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 888                                 'To save actions causing any more site replication lag, this parameter can make the client',
 889                                 'wait until the replication lag is less than the specified value.',
 890                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 891                                 '"Waiting for $host: $lag seconds lagged\n".',
 892                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 893                         ),
 894                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 895                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 896                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 897                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 898                         'origin' => array(
 899                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
 900                                 '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 .',
 901                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
 902                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
 903                         ),
 904                 );
 905         }
 906
 907         /**
 908          * See ApiBase for description.
 909          *
 910          * @return array
 911          */
 912         public function getDescription() {
 913                 return array(
 914                         '',
 915                         '',
 916                         '**********************************************************************************************************',
 917                         '**                                                                                                      **',
 918                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 919                         '**                                                                                                      **',
 920                         '**                                     Documentation and Examples:                                      **',
 921                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 922                         '**                                                                                                      **',
 923                         '**********************************************************************************************************',
 924                         '',
 925                         'Status:                All features shown on this page should be working, but the API',
 926                         '                       is still in active development, and may change at any time.',
 927                         '                       Make sure to monitor our mailing list for any updates',
 928                         '',
 929                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 930                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 931                         '                       header and the error code sent back will be set to the same value',
 932                         '',
 933                         '                       In the case of an invalid action being passed, these will have a value',
 934                         '                       of "unknown_action"',
 935                         '',
 936                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 937                         '',
 938                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 939                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 940                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 941                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 942                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 943                         '',
 944                         '',
 945                         '',
 946                         '',
 947                         '',
 948                 );
 949         }
 950
 951         /**
 952          * @return array
 953          */
 954         public function getPossibleErrors() {
 955                 return array_merge( parent::getPossibleErrors(), array(
 956                         array( 'readonlytext' ),
 957                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 958                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 959                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 960                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 961                 ) );
 962         }
 963
 964         /**
 965          * Returns an array of strings with credits for the API
 966          * @return array
 967          */
 968         protected function getCredits() {
 969                 return array(
 970                         'API developers:',
 971                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
 972                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 973                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 974                         '    Sam Reed - sam @ reedyboy . net',
 975                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
 976                         '',
 977                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 978                         'or file a bug report at https://bugzilla.wikimedia.org/'
 979                 );
 980         }
 981
 982         /**
 983          * Sets whether the pretty-printer should format *bold* and $italics$
 984          *
 985          * @param $help bool
 986          */
 987         public function setHelp( $help = true ) {
 988                 $this->mPrinter->setHelp( $help );
 989         }
 990
 991         /**
 992          * Override the parent to generate help messages for all available modules.
 993          *
 994          * @return string
 995          */
 996         public function makeHelpMsg() {
 997                 global $wgMemc, $wgAPICacheHelpTimeout;
 998                 $this->setHelp();
 999                 // Get help text from cache if present
1000                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1001                         SpecialVersion::getVersion( 'nodb' ) .
1002                         $this->getShowVersions() );
1003                 if ( $wgAPICacheHelpTimeout > 0 ) {
1004                         $cached = $wgMemc->get( $key );
1005                         if ( $cached ) {
1006                                 return $cached;
1007                         }
1008                 }
1009                 $retval = $this->reallyMakeHelpMsg();
1010                 if ( $wgAPICacheHelpTimeout > 0 ) {
1011                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1012                 }
1013                 return $retval;
1014         }
1015
1016         /**
1017          * @return mixed|string
1018          */
1019         public function reallyMakeHelpMsg() {
1020                 $this->setHelp();
1021
1022                 // Use parent to make default message for the main module
1023                 $msg = parent::makeHelpMsg();
1024
1025                 $astriks = str_repeat( '*** ', 14 );
1026                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1027                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1028                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1029                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1030                         $msg2 = $module->makeHelpMsg();
1031                         if ( $msg2 !== false ) {
1032                                 $msg .= $msg2;
1033                         }
1034                         $msg .= "\n";
1035                 }
1036
1037                 $msg .= "\n$astriks Permissions $astriks\n\n";
1038                 foreach ( self::$mRights as $right => $rightMsg ) {
1039                         $groups = User::getGroupsWithPermission( $right );
1040                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
1041                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1042
1043                 }
1044
1045                 $msg .= "\n$astriks Formats  $astriks\n\n";
1046                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1047                         $module = $this->createPrinterByName( $formatName );
1048                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1049                         $msg2 = $module->makeHelpMsg();
1050                         if ( $msg2 !== false ) {
1051                                 $msg .= $msg2;
1052                         }
1053                         $msg .= "\n";
1054                 }
1055
1056                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1057
1058                 return $msg;
1059         }
1060
1061         /**
1062          * @param $module ApiBase
1063          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1064          * @return string
1065          */
1066         public static function makeHelpMsgHeader( $module, $paramName ) {
1067                 $modulePrefix = $module->getModulePrefix();
1068                 if ( strval( $modulePrefix ) !== '' ) {
1069                         $modulePrefix = "($modulePrefix) ";
1070                 }
1071
1072                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1073         }
1074
1075         private $mCanApiHighLimits = null;
1076
1077         /**
1078          * Check whether the current user is allowed to use high limits
1079          * @return bool
1080          */
1081         public function canApiHighLimits() {
1082                 if ( !isset( $this->mCanApiHighLimits ) ) {
1083                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1084                 }
1085
1086                 return $this->mCanApiHighLimits;
1087         }
1088
1089         /**
1090          * Check whether the user wants us to show version information in the API help
1091          * @return bool
1092          */
1093         public function getShowVersions() {
1094                 return $this->mShowVersions;
1095         }
1096
1097         /**
1098          * Returns the version information of this file, plus it includes
1099          * the versions for all files that are not callable proper API modules
1100          *
1101          * @return array
1102          */
1103         public function getVersion() {
1104                 $vers = array();
1105                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1106                 $vers[] = __CLASS__ . ': $Id$';
1107                 $vers[] = ApiBase::getBaseVersion();
1108                 $vers[] = ApiFormatBase::getBaseVersion();
1109                 $vers[] = ApiQueryBase::getBaseVersion();
1110                 return $vers;
1111         }
1112
1113         /**
1114          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1115          * classes who wish to add their own modules to their lexicon or override the
1116          * behavior of inherent ones.
1117          *
1118          * @param $mdlName String The identifier for this module.
1119          * @param $mdlClass String The class where this module is implemented.
1120          */
1121         protected function addModule( $mdlName, $mdlClass ) {
1122                 $this->mModules[$mdlName] = $mdlClass;
1123         }
1124
1125         /**
1126          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1127          * classes who wish to add to or modify current formatters.
1128          *
1129          * @param $fmtName string The identifier for this format.
1130          * @param $fmtClass ApiFormatBase The class implementing this format.
1131          */
1132         protected function addFormat( $fmtName, $fmtClass ) {
1133                 $this->mFormats[$fmtName] = $fmtClass;
1134         }
1135
1136         /**
1137          * Get the array mapping module names to class names
1138          * @return array
1139          */
1140         function getModules() {
1141                 return $this->mModules;
1142         }
1143
1144         /**
1145          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1146          *
1147          * @since 1.18
1148          * @return array
1149          */
1150         public function getFormats() {
1151                 return $this->mFormats;
1152         }
1153 }
1154
1155 /**
1156  * This exception will be thrown when dieUsage is called to stop module execution.
1157  * The exception handling code will print a help screen explaining how this API may be used.
1158  *
1159  * @ingroup API
1160  */
1161 class UsageException extends MWException {
1162
1163         private $mCodestr;
1164
1165         /**
1166          * @var null|array
1167          */
1168         private $mExtraData;
1169
1170         /**
1171          * @param $message string
1172          * @param $codestr string
1173          * @param $code int
1174          * @param $extradata array|null
1175          */
1176         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1177                 parent::__construct( $message, $code );
1178                 $this->mCodestr = $codestr;
1179                 $this->mExtraData = $extradata;
1180         }
1181
1182         /**
1183          * @return string
1184          */
1185         public function getCodeString() {
1186                 return $this->mCodestr;
1187         }
1188
1189         /**
1190          * @return array
1191          */
1192         public function getMessageArray() {
1193                 $result = array(
1194                         'code' => $this->mCodestr,
1195                         'info' => $this->getMessage()
1196                 );
1197                 if ( is_array( $this->mExtraData ) ) {
1198                         $result = array_merge( $result, $this->mExtraData );
1199                 }
1200                 return $result;
1201         }
1202
1203         /**
1204          * @return string
1205          */
1206         public function __toString() {
1207                 return "{$this->getCodeString()}: {$this->getMessage()}";
1208         }
1209 }