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                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  69                 'rollback' => 'ApiRollback',
  70                 'delete' => 'ApiDelete',
  71                 'undelete' => 'ApiUndelete',
  72                 'protect' => 'ApiProtect',
  73                 'block' => 'ApiBlock',
  74                 'unblock' => 'ApiUnblock',
  75                 'move' => 'ApiMove',
  76                 'edit' => 'ApiEditPage',
  77                 'upload' => 'ApiUpload',
  78                 'filerevert' => 'ApiFileRevert',
  79                 'emailuser' => 'ApiEmailUser',
  80                 'watch' => 'ApiWatch',
  81                 'patrol' => 'ApiPatrol',
  82                 'import' => 'ApiImport',
  83                 'userrights' => 'ApiUserrights',
  84                 'options' => 'ApiOptions',
  85         );
  86
  87         /**
  88          * List of available formats: format name => format class
  89          */
  90         private static $Formats = array(
  91                 'json' => 'ApiFormatJson',
  92                 'jsonfm' => 'ApiFormatJson',
  93                 'php' => 'ApiFormatPhp',
  94                 'phpfm' => 'ApiFormatPhp',
  95                 'wddx' => 'ApiFormatWddx',
  96                 'wddxfm' => 'ApiFormatWddx',
  97                 'xml' => 'ApiFormatXml',
  98                 'xmlfm' => 'ApiFormatXml',
  99                 'yaml' => 'ApiFormatYaml',
 100                 'yamlfm' => 'ApiFormatYaml',
 101                 'rawfm' => 'ApiFormatJson',
 102                 'txt' => 'ApiFormatTxt',
 103                 'txtfm' => 'ApiFormatTxt',
 104                 'dbg' => 'ApiFormatDbg',
 105                 'dbgfm' => 'ApiFormatDbg',
 106                 'dump' => 'ApiFormatDump',
 107                 'dumpfm' => 'ApiFormatDump',
 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                         // Allow extra cleanup and logging
 372                         wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
 373
 374                         // Log it
 375                         if ( !( $e instanceof UsageException ) ) {
 376                                 wfDebugLog( 'exception', $e->getLogMessage() );
 377                         }
 378
 379                         // Handle any kind of exception by outputing properly formatted error message.
 380                         // If this fails, an unhandled exception should be thrown so that global error
 381                         // handler will process and log it.
 382
 383                         $errCode = $this->substituteResultWithError( $e );
 384
 385                         // Error results should not be cached
 386                         $this->setCacheMode( 'private' );
 387
 388                         $response = $this->getRequest()->response();
 389                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 390                         if ( $e->getCode() === 0 ) {
 391                                 $response->header( $headerStr );
 392                         } else {
 393                                 $response->header( $headerStr, true, $e->getCode() );
 394                         }
 395
 396                         // Reset and print just the error message
 397                         ob_clean();
 398
 399                         // If the error occurred during printing, do a printer->profileOut()
 400                         $this->mPrinter->safeProfileOut();
 401                         $this->printResult( true );
 402                 }
 403
 404                 // Send cache headers after any code which might generate an error, to
 405                 // avoid sending public cache headers for errors.
 406                 $this->sendCacheHeaders();
 407
 408                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 409                         echo wfReportTime();
 410                 }
 411
 412                 ob_end_flush();
 413         }
 414
 415         /**
 416          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 417          *
 418          * If no origin parameter is present, nothing happens.
 419          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 420          * is set and false is returned.
 421          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 422          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 423          * headers are set.
 424          *
 425          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 426          */
 427         protected function handleCORS() {
 428                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 429
 430                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 431                 if ( $originParam === null ) {
 432                         // No origin parameter, nothing to do
 433                         return true;
 434                 }
 435
 436                 $request = $this->getRequest();
 437                 $response = $request->response();
 438                 // Origin: header is a space-separated list of origins, check all of them
 439                 $originHeader = $request->getHeader( 'Origin' );
 440                 if ( $originHeader === false ) {
 441                         $origins = array();
 442                 } else {
 443                         $origins = explode( ' ', $originHeader );
 444                 }
 445                 if ( !in_array( $originParam, $origins ) ) {
 446                         // origin parameter set but incorrect
 447                         // Send a 403 response
 448                         $message = HttpStatus::getMessage( 403 );
 449                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 450                         $response->header( 'Cache-Control: no-cache' );
 451                         echo "'origin' parameter does not match Origin header\n";
 452                         return false;
 453                 }
 454                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 455                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 456                         $response->header( 'Access-Control-Allow-Credentials: true' );
 457                         $this->getOutput()->addVaryHeader( 'Origin' );
 458                 }
 459                 return true;
 460         }
 461
 462         /**
 463          * Attempt to match an Origin header against a set of rules and a set of exceptions
 464          * @param $value string Origin header
 465          * @param $rules array Set of wildcard rules
 466          * @param $exceptions array Set of wildcard rules
 467          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 468          */
 469         protected static function matchOrigin( $value, $rules, $exceptions ) {
 470                 foreach ( $rules as $rule ) {
 471                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 472                                 // Rule matches, check exceptions
 473                                 foreach ( $exceptions as $exc ) {
 474                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 475                                                 return false;
 476                                         }
 477                                 }
 478                                 return true;
 479                         }
 480                 }
 481                 return false;
 482         }
 483
 484         /**
 485          * Helper function to convert wildcard string into a regex
 486          * '*' => '.*?'
 487          * '?' => '.'
 488          *
 489          * @param $wildcard string String with wildcards
 490          * @return string Regular expression
 491          */
 492         protected static function wildcardToRegex( $wildcard ) {
 493                 $wildcard = preg_quote( $wildcard, '/' );
 494                 $wildcard = str_replace(
 495                         array( '\*', '\?' ),
 496                         array( '.*?', '.' ),
 497                         $wildcard
 498                 );
 499                 return "/https?:\/\/$wildcard/";
 500         }
 501
 502         protected function sendCacheHeaders() {
 503                 global $wgUseXVO, $wgVaryOnXFP;
 504                 $response = $this->getRequest()->response();
 505                 $out = $this->getOutput();
 506
 507                 if ( $wgVaryOnXFP ) {
 508                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 509                 }
 510
 511                 if ( $this->mCacheMode == 'private' ) {
 512                         $response->header( 'Cache-Control: private' );
 513                         return;
 514                 }
 515
 516                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 517                         $out->addVaryHeader( 'Cookie' );
 518                         $response->header( $out->getVaryHeader() );
 519                         if ( $wgUseXVO ) {
 520                                 $response->header( $out->getXVO() );
 521                                 if ( $out->haveCacheVaryCookies() ) {
 522                                         // Logged in, mark this request private
 523                                         $response->header( 'Cache-Control: private' );
 524                                         return;
 525                                 }
 526                                 // Logged out, send normal public headers below
 527                         } elseif ( session_id() != '' ) {
 528                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 529                                 // Mark request private
 530                                 $response->header( 'Cache-Control: private' );
 531                                 return;
 532                         } // else no XVO and anonymous, send public headers below
 533                 }
 534
 535                 // Send public headers
 536                 $response->header( $out->getVaryHeader() );
 537                 if ( $wgUseXVO ) {
 538                         $response->header( $out->getXVO() );
 539                 }
 540
 541                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 542                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 543                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 544                 }
 545                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 546                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 547                 }
 548
 549                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 550                         // Public cache not requested
 551                         // Sending a Vary header in this case is harmless, and protects us
 552                         // against conditional calls of setCacheMaxAge().
 553                         $response->header( 'Cache-Control: private' );
 554                         return;
 555                 }
 556
 557                 $this->mCacheControl['public'] = true;
 558
 559                 // Send an Expires header
 560                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 561                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 562                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 563
 564                 // Construct the Cache-Control header
 565                 $ccHeader = '';
 566                 $separator = '';
 567                 foreach ( $this->mCacheControl as $name => $value ) {
 568                         if ( is_bool( $value ) ) {
 569                                 if ( $value ) {
 570                                         $ccHeader .= $separator . $name;
 571                                         $separator = ', ';
 572                                 }
 573                         } else {
 574                                 $ccHeader .= $separator . "$name=$value";
 575                                 $separator = ', ';
 576                         }
 577                 }
 578
 579                 $response->header( "Cache-Control: $ccHeader" );
 580         }
 581
 582         /**
 583          * Replace the result data with the information about an exception.
 584          * Returns the error code
 585          * @param $e Exception
 586          * @return string
 587          */
 588         protected function substituteResultWithError( $e ) {
 589                 global $wgShowHostnames;
 590
 591                 $result = $this->getResult();
 592                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 593                 if ( !isset ( $this->mPrinter ) ) {
 594                         // The printer has not been created yet. Try to manually get formatter value.
 595                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 596                         if ( !in_array( $value, $this->mFormatNames ) ) {
 597                                 $value = self::API_DEFAULT_FORMAT;
 598                         }
 599
 600                         $this->mPrinter = $this->createPrinterByName( $value );
 601                         if ( $this->mPrinter->getNeedsRawData() ) {
 602                                 $result->setRawMode();
 603                         }
 604                 }
 605
 606                 if ( $e instanceof UsageException ) {
 607                         // User entered incorrect parameters - print usage screen
 608                         $errMessage = $e->getMessageArray();
 609
 610                         // Only print the help message when this is for the developer, not runtime
 611                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 612                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 613                         }
 614
 615                 } else {
 616                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 617                         // Something is seriously wrong
 618                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 619                                 $info = 'Database query error';
 620                         } else {
 621                                 $info = "Exception Caught: {$e->getMessage()}";
 622                         }
 623
 624                         $errMessage = array(
 625                                 'code' => 'internal_api_error_' . get_class( $e ),
 626                                 'info' => $info,
 627                         );
 628                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 629                 }
 630
 631                 $result->reset();
 632                 $result->disableSizeCheck();
 633                 // Re-add the id
 634                 $requestid = $this->getParameter( 'requestid' );
 635                 if ( !is_null( $requestid ) ) {
 636                         $result->addValue( null, 'requestid', $requestid );
 637                 }
 638
 639                 if ( $wgShowHostnames ) {
 640                         // servedby is especially useful when debugging errors
 641                         $result->addValue( null, 'servedby', wfHostName() );
 642                 }
 643
 644                 $result->addValue( null, 'error', $errMessage );
 645
 646                 return $errMessage['code'];
 647         }
 648
 649         /**
 650          * Set up for the execution.
 651          * @return array
 652          */
 653         protected function setupExecuteAction() {
 654                 global $wgShowHostnames;
 655
 656                 // First add the id to the top element
 657                 $result = $this->getResult();
 658                 $requestid = $this->getParameter( 'requestid' );
 659                 if ( !is_null( $requestid ) ) {
 660                         $result->addValue( null, 'requestid', $requestid );
 661                 }
 662
 663                 if ( $wgShowHostnames ) {
 664                         $servedby = $this->getParameter( 'servedby' );
 665                         if ( $servedby ) {
 666                                 $result->addValue( null, 'servedby', wfHostName() );
 667                         }
 668                 }
 669
 670                 $params = $this->extractRequestParams();
 671
 672                 $this->mShowVersions = $params['version'];
 673                 $this->mAction = $params['action'];
 674
 675                 if ( !is_string( $this->mAction ) ) {
 676                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 677                 }
 678
 679                 return $params;
 680         }
 681
 682         /**
 683          * Set up the module for response
 684          * @return ApiBase The module that will handle this action
 685          */
 686         protected function setupModule() {
 687                 // Instantiate the module requested by the user
 688                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 689                 $this->mModule = $module;
 690
 691                 $moduleParams = $module->extractRequestParams();
 692
 693                 // Die if token required, but not provided (unless there is a gettoken parameter)
 694                 if ( isset( $moduleParams['gettoken'] ) ) {
 695                         $gettoken = $moduleParams['gettoken'];
 696                 } else {
 697                         $gettoken = false;
 698                 }
 699
 700                 $salt = $module->getTokenSalt();
 701                 if ( $salt !== false && !$gettoken ) {
 702                         if ( !isset( $moduleParams['token'] ) ) {
 703                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 704                         } else {
 705                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 706                                         $this->dieUsageMsg( 'sessionfailure' );
 707                                 }
 708                         }
 709                 }
 710                 return $module;
 711         }
 712
 713         /**
 714          * Check the max lag if necessary
 715          * @param $module ApiBase object: Api module being used
 716          * @param $params Array an array containing the request parameters.
 717          * @return boolean True on success, false should exit immediately
 718          */
 719         protected function checkMaxLag( $module, $params ) {
 720                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 721                         // Check for maxlag
 722                         global $wgShowHostnames;
 723                         $maxLag = $params['maxlag'];
 724                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 725                         if ( $lag > $maxLag ) {
 726                                 $response = $this->getRequest()->response();
 727
 728                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 729                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 730
 731                                 if ( $wgShowHostnames ) {
 732                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 733                                 } else {
 734                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 735                                 }
 736                                 return false;
 737                         }
 738                 }
 739                 return true;
 740         }
 741
 742         /**
 743          * Check for sufficient permissions to execute
 744          * @param $module ApiBase An Api module
 745          */
 746         protected function checkExecutePermissions( $module ) {
 747                 $user = $this->getUser();
 748                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 749                         !$user->isAllowed( 'read' ) )
 750                 {
 751                         $this->dieUsageMsg( 'readrequired' );
 752                 }
 753                 if ( $module->isWriteMode() ) {
 754                         if ( !$this->mEnableWrite ) {
 755                                 $this->dieUsageMsg( 'writedisabled' );
 756                         }
 757                         if ( !$user->isAllowed( 'writeapi' ) ) {
 758                                 $this->dieUsageMsg( 'writerequired' );
 759                         }
 760                         if ( wfReadOnly() ) {
 761                                 $this->dieReadOnly();
 762                         }
 763                 }
 764         }
 765
 766         /**
 767          * Check POST for external response and setup result printer
 768          * @param $module ApiBase An Api module
 769          * @param $params Array an array with the request parameters
 770          */
 771         protected function setupExternalResponse( $module, $params ) {
 772                 // Ignore mustBePosted() for internal calls
 773                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 774                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 775                 }
 776
 777                 // See if custom printer is used
 778                 $this->mPrinter = $module->getCustomPrinter();
 779                 if ( is_null( $this->mPrinter ) ) {
 780                         // Create an appropriate printer
 781                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 782                 }
 783
 784                 if ( $this->mPrinter->getNeedsRawData() ) {
 785                         $this->getResult()->setRawMode();
 786                 }
 787         }
 788
 789         /**
 790          * Execute the actual module, without any error handling
 791          */
 792         protected function executeAction() {
 793                 $params = $this->setupExecuteAction();
 794                 $module = $this->setupModule();
 795
 796                 $this->checkExecutePermissions( $module );
 797
 798                 if ( !$this->checkMaxLag( $module, $params ) ) {
 799                         return;
 800                 }
 801
 802                 if ( !$this->mInternalMode ) {
 803                         $this->setupExternalResponse( $module, $params );
 804                 }
 805
 806                 // Execute
 807                 $module->profileIn();
 808                 $module->execute();
 809                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 810                 $module->profileOut();
 811
 812                 if ( !$this->mInternalMode ) {
 813                         //append Debug information
 814                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 815
 816                         // Print result data
 817                         $this->printResult( false );
 818                 }
 819         }
 820
 821         /**
 822          * Print results using the current printer
 823          *
 824          * @param $isError bool
 825          */
 826         protected function printResult( $isError ) {
 827                 $this->getResult()->cleanUpUTF8();
 828                 $printer = $this->mPrinter;
 829                 $printer->profileIn();
 830
 831                 /**
 832                  * If the help message is requested in the default (xmlfm) format,
 833                  * tell the printer not to escape ampersands so that our links do
 834                  * not break.
 835                  */
 836                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 837                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 838
 839                 $printer->initPrinter( $isError );
 840
 841                 $printer->execute();
 842                 $printer->closePrinter();
 843                 $printer->profileOut();
 844         }
 845
 846         /**
 847          * @return bool
 848          */
 849         public function isReadMode() {
 850                 return false;
 851         }
 852
 853         /**
 854          * See ApiBase for description.
 855          *
 856          * @return array
 857          */
 858         public function getAllowedParams() {
 859                 return array(
 860                         'format' => array(
 861                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 862                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 863                         ),
 864                         'action' => array(
 865                                 ApiBase::PARAM_DFLT => 'help',
 866                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 867                         ),
 868                         'version' => false,
 869                         'maxlag'  => array(
 870                                 ApiBase::PARAM_TYPE => 'integer'
 871                         ),
 872                         'smaxage' => array(
 873                                 ApiBase::PARAM_TYPE => 'integer',
 874                                 ApiBase::PARAM_DFLT => 0
 875                         ),
 876                         'maxage' => array(
 877                                 ApiBase::PARAM_TYPE => 'integer',
 878                                 ApiBase::PARAM_DFLT => 0
 879                         ),
 880                         'requestid' => null,
 881                         'servedby'  => false,
 882                         'origin' => null,
 883                 );
 884         }
 885
 886         /**
 887          * See ApiBase for description.
 888          *
 889          * @return array
 890          */
 891         public function getParamDescription() {
 892                 return array(
 893                         'format' => 'The format of the output',
 894                         'action' => 'What action you would like to perform. See below for module help',
 895                         'version' => 'When showing help, include version for each module',
 896                         'maxlag' => array(
 897                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 898                                 'To save actions causing any more site replication lag, this parameter can make the client',
 899                                 'wait until the replication lag is less than the specified value.',
 900                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 901                                 '"Waiting for $host: $lag seconds lagged\n".',
 902                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 903                         ),
 904                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 905                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 906                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 907                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 908                         'origin' => array(
 909                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
 910                                 '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 .',
 911                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
 912                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
 913                         ),
 914                 );
 915         }
 916
 917         /**
 918          * See ApiBase for description.
 919          *
 920          * @return array
 921          */
 922         public function getDescription() {
 923                 return array(
 924                         '',
 925                         '',
 926                         '**********************************************************************************************************',
 927                         '**                                                                                                      **',
 928                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 929                         '**                                                                                                      **',
 930                         '**                                     Documentation and Examples:                                      **',
 931                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 932                         '**                                                                                                      **',
 933                         '**********************************************************************************************************',
 934                         '',
 935                         'Status:                All features shown on this page should be working, but the API',
 936                         '                       is still in active development, and may change at any time.',
 937                         '                       Make sure to monitor our mailing list for any updates',
 938                         '',
 939                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 940                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 941                         '                       header and the error code sent back will be set to the same value',
 942                         '',
 943                         '                       In the case of an invalid action being passed, these will have a value',
 944                         '                       of "unknown_action"',
 945                         '',
 946                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 947                         '',
 948                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 949                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 950                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 951                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 952                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 953                         '',
 954                         '',
 955                         '',
 956                         '',
 957                         '',
 958                 );
 959         }
 960
 961         /**
 962          * @return array
 963          */
 964         public function getPossibleErrors() {
 965                 return array_merge( parent::getPossibleErrors(), array(
 966                         array( 'readonlytext' ),
 967                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 968                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 969                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 970                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 971                 ) );
 972         }
 973
 974         /**
 975          * Returns an array of strings with credits for the API
 976          * @return array
 977          */
 978         protected function getCredits() {
 979                 return array(
 980                         'API developers:',
 981                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
 982                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 983                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 984                         '    Sam Reed - sam @ reedyboy . net',
 985                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
 986                         '',
 987                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 988                         'or file a bug report at https://bugzilla.wikimedia.org/'
 989                 );
 990         }
 991
 992         /**
 993          * Sets whether the pretty-printer should format *bold* and $italics$
 994          *
 995          * @param $help bool
 996          */
 997         public function setHelp( $help = true ) {
 998                 $this->mPrinter->setHelp( $help );
 999         }
1000
1001         /**
1002          * Override the parent to generate help messages for all available modules.
1003          *
1004          * @return string
1005          */
1006         public function makeHelpMsg() {
1007                 global $wgMemc, $wgAPICacheHelpTimeout;
1008                 $this->setHelp();
1009                 // Get help text from cache if present
1010                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1011                         SpecialVersion::getVersion( 'nodb' ) .
1012                         $this->getShowVersions() );
1013                 if ( $wgAPICacheHelpTimeout > 0 ) {
1014                         $cached = $wgMemc->get( $key );
1015                         if ( $cached ) {
1016                                 return $cached;
1017                         }
1018                 }
1019                 $retval = $this->reallyMakeHelpMsg();
1020                 if ( $wgAPICacheHelpTimeout > 0 ) {
1021                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1022                 }
1023                 return $retval;
1024         }
1025
1026         /**
1027          * @return mixed|string
1028          */
1029         public function reallyMakeHelpMsg() {
1030                 $this->setHelp();
1031
1032                 // Use parent to make default message for the main module
1033                 $msg = parent::makeHelpMsg();
1034
1035                 $astriks = str_repeat( '*** ', 14 );
1036                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1037                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1038                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1039                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1040                         $msg2 = $module->makeHelpMsg();
1041                         if ( $msg2 !== false ) {
1042                                 $msg .= $msg2;
1043                         }
1044                         $msg .= "\n";
1045                 }
1046
1047                 $msg .= "\n$astriks Permissions $astriks\n\n";
1048                 foreach ( self::$mRights as $right => $rightMsg ) {
1049                         $groups = User::getGroupsWithPermission( $right );
1050                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
1051                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1052
1053                 }
1054
1055                 $msg .= "\n$astriks Formats  $astriks\n\n";
1056                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1057                         $module = $this->createPrinterByName( $formatName );
1058                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1059                         $msg2 = $module->makeHelpMsg();
1060                         if ( $msg2 !== false ) {
1061                                 $msg .= $msg2;
1062                         }
1063                         $msg .= "\n";
1064                 }
1065
1066                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1067
1068                 return $msg;
1069         }
1070
1071         /**
1072          * @param $module ApiBase
1073          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1074          * @return string
1075          */
1076         public static function makeHelpMsgHeader( $module, $paramName ) {
1077                 $modulePrefix = $module->getModulePrefix();
1078                 if ( strval( $modulePrefix ) !== '' ) {
1079                         $modulePrefix = "($modulePrefix) ";
1080                 }
1081
1082                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1083         }
1084
1085         private $mCanApiHighLimits = null;
1086
1087         /**
1088          * Check whether the current user is allowed to use high limits
1089          * @return bool
1090          */
1091         public function canApiHighLimits() {
1092                 if ( !isset( $this->mCanApiHighLimits ) ) {
1093                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1094                 }
1095
1096                 return $this->mCanApiHighLimits;
1097         }
1098
1099         /**
1100          * Check whether the user wants us to show version information in the API help
1101          * @return bool
1102          */
1103         public function getShowVersions() {
1104                 return $this->mShowVersions;
1105         }
1106
1107         /**
1108          * Returns the version information of this file, plus it includes
1109          * the versions for all files that are not callable proper API modules
1110          *
1111          * @return array
1112          */
1113         public function getVersion() {
1114                 $vers = array();
1115                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1116                 $vers[] = __CLASS__ . ': $Id$';
1117                 $vers[] = ApiBase::getBaseVersion();
1118                 $vers[] = ApiFormatBase::getBaseVersion();
1119                 $vers[] = ApiQueryBase::getBaseVersion();
1120                 return $vers;
1121         }
1122
1123         /**
1124          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1125          * classes who wish to add their own modules to their lexicon or override the
1126          * behavior of inherent ones.
1127          *
1128          * @param $mdlName String The identifier for this module.
1129          * @param $mdlClass String The class where this module is implemented.
1130          */
1131         protected function addModule( $mdlName, $mdlClass ) {
1132                 $this->mModules[$mdlName] = $mdlClass;
1133         }
1134
1135         /**
1136          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1137          * classes who wish to add to or modify current formatters.
1138          *
1139          * @param $fmtName string The identifier for this format.
1140          * @param $fmtClass ApiFormatBase The class implementing this format.
1141          */
1142         protected function addFormat( $fmtName, $fmtClass ) {
1143                 $this->mFormats[$fmtName] = $fmtClass;
1144         }
1145
1146         /**
1147          * Get the array mapping module names to class names
1148          * @return array
1149          */
1150         function getModules() {
1151                 return $this->mModules;
1152         }
1153
1154         /**
1155          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1156          *
1157          * @since 1.18
1158          * @return array
1159          */
1160         public function getFormats() {
1161                 return $this->mFormats;
1162         }
1163 }
1164
1165 /**
1166  * This exception will be thrown when dieUsage is called to stop module execution.
1167  * The exception handling code will print a help screen explaining how this API may be used.
1168  *
1169  * @ingroup API
1170  */
1171 class UsageException extends MWException {
1172
1173         private $mCodestr;
1174
1175         /**
1176          * @var null|array
1177          */
1178         private $mExtraData;
1179
1180         /**
1181          * @param $message string
1182          * @param $codestr string
1183          * @param $code int
1184          * @param $extradata array|null
1185          */
1186         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1187                 parent::__construct( $message, $code );
1188                 $this->mCodestr = $codestr;
1189                 $this->mExtraData = $extradata;
1190         }
1191
1192         /**
1193          * @return string
1194          */
1195         public function getCodeString() {
1196                 return $this->mCodestr;
1197         }
1198
1199         /**
1200          * @return array
1201          */
1202         public function getMessageArray() {
1203                 $result = array(
1204                         'code' => $this->mCodestr,
1205                         'info' => $this->getMessage()
1206                 );
1207                 if ( is_array( $this->mExtraData ) ) {
1208                         $result = array_merge( $result, $this->mExtraData );
1209                 }
1210                 return $result;
1211         }
1212
1213         /**
1214          * @return string
1215          */
1216         public function __toString() {
1217                 return "{$this->getCodeString()}: {$this->getMessage()}";
1218         }
1219 }