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                 'none' => 'ApiFormatNone',
 109         );
 110
 111         /**
 112          * List of user roles that are specifically relevant to the API.
 113          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 114          *                           'params' => array ( $someVarToSubst ) ),
 115          *                          );
 116          */
 117         private static $mRights = array(
 118                 'writeapi' => array(
 119                         'msg' => 'Use of the write API',
 120                         'params' => array()
 121                 ),
 122                 'apihighlimits' => array(
 123                         '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.',
 124                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 125                 )
 126         );
 127
 128         /**
 129          * @var ApiFormatBase
 130          */
 131         private $mPrinter;
 132
 133         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 134         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 135         private $mInternalMode, $mSquidMaxage, $mModule;
 136
 137         private $mCacheMode = 'private';
 138         private $mCacheControl = array();
 139
 140         /**
 141          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 142          *
 143          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 144          * @param $enableWrite bool should be set to true if the api may modify data
 145          */
 146         public function __construct( $context = null, $enableWrite = false ) {
 147                 if ( $context === null ) {
 148                         $context = RequestContext::getMain();
 149                 } elseif ( $context instanceof WebRequest ) {
 150                         // BC for pre-1.19
 151                         $request = $context;
 152                         $context = RequestContext::getMain();
 153                 }
 154                 // We set a derivative context so we can change stuff later
 155                 $this->setContext( new DerivativeContext( $context ) );
 156
 157                 if ( isset( $request ) ) {
 158                         $this->getContext()->setRequest( $request );
 159                 }
 160
 161                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 162
 163                 // Special handling for the main module: $parent === $this
 164                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 165
 166                 if ( !$this->mInternalMode ) {
 167                         // Impose module restrictions.
 168                         // If the current user cannot read,
 169                         // Remove all modules other than login
 170                         global $wgUser;
 171
 172                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 173                                 // JSON callback allows cross-site reads.
 174                                 // For safety, strip user credentials.
 175                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 176                                 $wgUser = new User();
 177                                 $this->getContext()->setUser( $wgUser );
 178                         }
 179                 }
 180
 181                 global $wgAPIModules; // extension modules
 182                 $this->mModules = $wgAPIModules + self::$Modules;
 183
 184                 $this->mModuleNames = array_keys( $this->mModules );
 185                 $this->mFormats = self::$Formats;
 186                 $this->mFormatNames = array_keys( $this->mFormats );
 187
 188                 $this->mResult = new ApiResult( $this );
 189                 $this->mShowVersions = false;
 190                 $this->mEnableWrite = $enableWrite;
 191
 192                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 193                 $this->mCommit = false;
 194         }
 195
 196         /**
 197          * Return true if the API was started by other PHP code using FauxRequest
 198          * @return bool
 199          */
 200         public function isInternalMode() {
 201                 return $this->mInternalMode;
 202         }
 203
 204         /**
 205          * Get the ApiResult object associated with current request
 206          *
 207          * @return ApiResult
 208          */
 209         public function getResult() {
 210                 return $this->mResult;
 211         }
 212
 213         /**
 214          * Get the API module object. Only works after executeAction()
 215          *
 216          * @return ApiBase
 217          */
 218         public function getModule() {
 219                 return $this->mModule;
 220         }
 221
 222         /**
 223          * Get the result formatter object. Only works after setupExecuteAction()
 224          *
 225          * @return ApiFormatBase
 226          */
 227         public function getPrinter() {
 228                 return $this->mPrinter;
 229         }
 230
 231         /**
 232          * Set how long the response should be cached.
 233          *
 234          * @param $maxage
 235          */
 236         public function setCacheMaxAge( $maxage ) {
 237                 $this->setCacheControl( array(
 238                         'max-age' => $maxage,
 239                         's-maxage' => $maxage
 240                 ) );
 241         }
 242
 243         /**
 244          * Set the type of caching headers which will be sent.
 245          *
 246          * @param $mode String One of:
 247          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 248          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 249          *         not provided by any of these means, the object will be private.
 250          *    - 'private':    Cache this object only in private client-side caches.
 251          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 252          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 253          *         set consistently for a given URL, it cannot be set differently depending on
 254          *         things like the contents of the database, or whether the user is logged in.
 255          *
 256          *  If the wiki does not allow anonymous users to read it, the mode set here
 257          *  will be ignored, and private caching headers will always be sent. In other words,
 258          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 259          *  view.
 260          *
 261          *  For user-dependent data, the private mode should generally be used. The
 262          *  anon-public-user-private mode should only be used where there is a particularly
 263          *  good performance reason for caching the anonymous response, but where the
 264          *  response to logged-in users may differ, or may contain private data.
 265          *
 266          *  If this function is never called, then the default will be the private mode.
 267          */
 268         public function setCacheMode( $mode ) {
 269                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 270                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 271                         // Ignore for forwards-compatibility
 272                         return;
 273                 }
 274
 275                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 276                         // Private wiki, only private headers
 277                         if ( $mode !== 'private' ) {
 278                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 279                                 return;
 280                         }
 281                 }
 282
 283                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 284                 $this->mCacheMode = $mode;
 285         }
 286
 287         /**
 288          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 289          * need to call this function. If there is a need, you can use
 290          * $this->setCacheMode('private')
 291          */
 292         public function setCachePrivate() {
 293                 wfDeprecated( __METHOD__, '1.17' );
 294                 $this->setCacheMode( 'private' );
 295         }
 296
 297         /**
 298          * Set directives (key/value pairs) for the Cache-Control header.
 299          * Boolean values will be formatted as such, by including or omitting
 300          * without an equals sign.
 301          *
 302          * Cache control values set here will only be used if the cache mode is not
 303          * private, see setCacheMode().
 304          *
 305          * @param $directives array
 306          */
 307         public function setCacheControl( $directives ) {
 308                 $this->mCacheControl = $directives + $this->mCacheControl;
 309         }
 310
 311         /**
 312          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 313          * may be cached for anons but may not be cached for logged-in users.
 314          *
 315          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 316          * given URL must either always or never call this function; if it sometimes does and
 317          * sometimes doesn't, stuff will break.
 318          *
 319          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 320          */
 321         public function setVaryCookie() {
 322                 wfDeprecated( __METHOD__, '1.17' );
 323                 $this->setCacheMode( 'anon-public-user-private' );
 324         }
 325
 326         /**
 327          * Create an instance of an output formatter by its name
 328          *
 329          * @param $format string
 330          *
 331          * @return ApiFormatBase
 332          */
 333         public function createPrinterByName( $format ) {
 334                 if ( !isset( $this->mFormats[$format] ) ) {
 335                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 336                 }
 337                 return new $this->mFormats[$format] ( $this, $format );
 338         }
 339
 340         /**
 341          * Execute api request. Any errors will be handled if the API was called by the remote client.
 342          */
 343         public function execute() {
 344                 $this->profileIn();
 345                 if ( $this->mInternalMode ) {
 346                         $this->executeAction();
 347                 } else {
 348                         $this->executeActionWithErrorHandling();
 349                 }
 350
 351                 $this->profileOut();
 352         }
 353
 354         /**
 355          * Execute an action, and in case of an error, erase whatever partial results
 356          * have been accumulated, and replace it with an error message and a help screen.
 357          */
 358         protected function executeActionWithErrorHandling() {
 359                 // Verify the CORS header before executing the action
 360                 if ( !$this->handleCORS() ) {
 361                         // handleCORS() has sent a 403, abort
 362                         return;
 363                 }
 364
 365                 // In case an error occurs during data output,
 366                 // clear the output buffer and print just the error information
 367                 ob_start();
 368
 369                 try {
 370                         $this->executeAction();
 371                 } catch ( Exception $e ) {
 372                         // Log it
 373                         if ( !( $e instanceof UsageException ) ) {
 374                                 wfDebugLog( 'exception', $e->getLogMessage() );
 375                         }
 376
 377                         // Handle any kind of exception by outputing properly formatted error message.
 378                         // If this fails, an unhandled exception should be thrown so that global error
 379                         // handler will process and log it.
 380
 381                         $errCode = $this->substituteResultWithError( $e );
 382
 383                         // Error results should not be cached
 384                         $this->setCacheMode( 'private' );
 385
 386                         $response = $this->getRequest()->response();
 387                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 388                         if ( $e->getCode() === 0 ) {
 389                                 $response->header( $headerStr );
 390                         } else {
 391                                 $response->header( $headerStr, true, $e->getCode() );
 392                         }
 393
 394                         // Reset and print just the error message
 395                         ob_clean();
 396
 397                         // If the error occurred during printing, do a printer->profileOut()
 398                         $this->mPrinter->safeProfileOut();
 399                         $this->printResult( true );
 400                 }
 401
 402                 // Send cache headers after any code which might generate an error, to
 403                 // avoid sending public cache headers for errors.
 404                 $this->sendCacheHeaders();
 405
 406                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 407                         echo wfReportTime();
 408                 }
 409
 410                 ob_end_flush();
 411         }
 412
 413         /**
 414          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 415          *
 416          * If no origin parameter is present, nothing happens.
 417          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 418          * is set and false is returned.
 419          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 420          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 421          * headers are set.
 422          *
 423          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 424          */
 425         protected function handleCORS() {
 426                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 427
 428                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 429                 if ( $originParam === null ) {
 430                         // No origin parameter, nothing to do
 431                         return true;
 432                 }
 433
 434                 $request = $this->getRequest();
 435                 $response = $request->response();
 436                 // Origin: header is a space-separated list of origins, check all of them
 437                 $originHeader = $request->getHeader( 'Origin' );
 438                 if ( $originHeader === false ) {
 439                         $origins = array();
 440                 } else {
 441                         $origins = explode( ' ', $originHeader );
 442                 }
 443                 if ( !in_array( $originParam, $origins ) ) {
 444                         // origin parameter set but incorrect
 445                         // Send a 403 response
 446                         $message = HttpStatus::getMessage( 403 );
 447                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 448                         $response->header( 'Cache-Control: no-cache' );
 449                         echo "'origin' parameter does not match Origin header\n";
 450                         return false;
 451                 }
 452                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 453                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 454                         $response->header( 'Access-Control-Allow-Credentials: true' );
 455                         $this->getOutput()->addVaryHeader( 'Origin' );
 456                 }
 457                 return true;
 458         }
 459
 460         /**
 461          * Attempt to match an Origin header against a set of rules and a set of exceptions
 462          * @param $value string Origin header
 463          * @param $rules array Set of wildcard rules
 464          * @param $exceptions array Set of wildcard rules
 465          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 466          */
 467         protected static function matchOrigin( $value, $rules, $exceptions ) {
 468                 foreach ( $rules as $rule ) {
 469                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 470                                 // Rule matches, check exceptions
 471                                 foreach ( $exceptions as $exc ) {
 472                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 473                                                 return false;
 474                                         }
 475                                 }
 476                                 return true;
 477                         }
 478                 }
 479                 return false;
 480         }
 481
 482         /**
 483          * Helper function to convert wildcard string into a regex
 484          * '*' => '.*?'
 485          * '?' => '.'
 486          *
 487          * @param $wildcard string String with wildcards
 488          * @return string Regular expression
 489          */
 490         protected static function wildcardToRegex( $wildcard ) {
 491                 $wildcard = preg_quote( $wildcard, '/' );
 492                 $wildcard = str_replace(
 493                         array( '\*', '\?' ),
 494                         array( '.*?', '.' ),
 495                         $wildcard
 496                 );
 497                 return "/https?:\/\/$wildcard/";
 498         }
 499
 500         protected function sendCacheHeaders() {
 501                 global $wgUseXVO, $wgVaryOnXFP;
 502                 $response = $this->getRequest()->response();
 503                 $out = $this->getOutput();
 504
 505                 if ( $wgVaryOnXFP ) {
 506                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 507                 }
 508
 509                 if ( $this->mCacheMode == 'private' ) {
 510                         $response->header( 'Cache-Control: private' );
 511                         return;
 512                 }
 513
 514                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 515                         $out->addVaryHeader( 'Cookie' );
 516                         $response->header( $out->getVaryHeader() );
 517                         if ( $wgUseXVO ) {
 518                                 $response->header( $out->getXVO() );
 519                                 if ( $out->haveCacheVaryCookies() ) {
 520                                         // Logged in, mark this request private
 521                                         $response->header( 'Cache-Control: private' );
 522                                         return;
 523                                 }
 524                                 // Logged out, send normal public headers below
 525                         } elseif ( session_id() != '' ) {
 526                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 527                                 // Mark request private
 528                                 $response->header( 'Cache-Control: private' );
 529                                 return;
 530                         } // else no XVO and anonymous, send public headers below
 531                 }
 532
 533                 // Send public headers
 534                 $response->header( $out->getVaryHeader() );
 535                 if ( $wgUseXVO ) {
 536                         $response->header( $out->getXVO() );
 537                 }
 538
 539                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 540                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 541                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 542                 }
 543                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 544                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 545                 }
 546
 547                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 548                         // Public cache not requested
 549                         // Sending a Vary header in this case is harmless, and protects us
 550                         // against conditional calls of setCacheMaxAge().
 551                         $response->header( 'Cache-Control: private' );
 552                         return;
 553                 }
 554
 555                 $this->mCacheControl['public'] = true;
 556
 557                 // Send an Expires header
 558                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 559                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 560                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 561
 562                 // Construct the Cache-Control header
 563                 $ccHeader = '';
 564                 $separator = '';
 565                 foreach ( $this->mCacheControl as $name => $value ) {
 566                         if ( is_bool( $value ) ) {
 567                                 if ( $value ) {
 568                                         $ccHeader .= $separator . $name;
 569                                         $separator = ', ';
 570                                 }
 571                         } else {
 572                                 $ccHeader .= $separator . "$name=$value";
 573                                 $separator = ', ';
 574                         }
 575                 }
 576
 577                 $response->header( "Cache-Control: $ccHeader" );
 578         }
 579
 580         /**
 581          * Replace the result data with the information about an exception.
 582          * Returns the error code
 583          * @param $e Exception
 584          * @return string
 585          */
 586         protected function substituteResultWithError( $e ) {
 587                 global $wgShowHostnames;
 588
 589                 $result = $this->getResult();
 590                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 591                 if ( !isset ( $this->mPrinter ) ) {
 592                         // The printer has not been created yet. Try to manually get formatter value.
 593                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 594                         if ( !in_array( $value, $this->mFormatNames ) ) {
 595                                 $value = self::API_DEFAULT_FORMAT;
 596                         }
 597
 598                         $this->mPrinter = $this->createPrinterByName( $value );
 599                         if ( $this->mPrinter->getNeedsRawData() ) {
 600                                 $result->setRawMode();
 601                         }
 602                 }
 603
 604                 if ( $e instanceof UsageException ) {
 605                         // User entered incorrect parameters - print usage screen
 606                         $errMessage = $e->getMessageArray();
 607
 608                         // Only print the help message when this is for the developer, not runtime
 609                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 610                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 611                         }
 612
 613                 } else {
 614                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 615                         // Something is seriously wrong
 616                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 617                                 $info = 'Database query error';
 618                         } else {
 619                                 $info = "Exception Caught: {$e->getMessage()}";
 620                         }
 621
 622                         $errMessage = array(
 623                                 'code' => 'internal_api_error_' . get_class( $e ),
 624                                 'info' => $info,
 625                         );
 626                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 627                 }
 628
 629                 $result->reset();
 630                 $result->disableSizeCheck();
 631                 // Re-add the id
 632                 $requestid = $this->getParameter( 'requestid' );
 633                 if ( !is_null( $requestid ) ) {
 634                         $result->addValue( null, 'requestid', $requestid );
 635                 }
 636
 637                 if ( $wgShowHostnames ) {
 638                         // servedby is especially useful when debugging errors
 639                         $result->addValue( null, 'servedby', wfHostName() );
 640                 }
 641
 642                 $result->addValue( null, 'error', $errMessage );
 643
 644                 return $errMessage['code'];
 645         }
 646
 647         /**
 648          * Set up for the execution.
 649          * @return array
 650          */
 651         protected function setupExecuteAction() {
 652                 global $wgShowHostnames;
 653
 654                 // First add the id to the top element
 655                 $result = $this->getResult();
 656                 $requestid = $this->getParameter( 'requestid' );
 657                 if ( !is_null( $requestid ) ) {
 658                         $result->addValue( null, 'requestid', $requestid );
 659                 }
 660
 661                 if ( $wgShowHostnames ) {
 662                         $servedby = $this->getParameter( 'servedby' );
 663                         if ( $servedby ) {
 664                                 $result->addValue( null, 'servedby', wfHostName() );
 665                         }
 666                 }
 667
 668                 $params = $this->extractRequestParams();
 669
 670                 $this->mShowVersions = $params['version'];
 671                 $this->mAction = $params['action'];
 672
 673                 if ( !is_string( $this->mAction ) ) {
 674                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 675                 }
 676
 677                 return $params;
 678         }
 679
 680         /**
 681          * Set up the module for response
 682          * @return ApiBase The module that will handle this action
 683          */
 684         protected function setupModule() {
 685                 // Instantiate the module requested by the user
 686                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 687                 $this->mModule = $module;
 688
 689                 $moduleParams = $module->extractRequestParams();
 690
 691                 // Die if token required, but not provided (unless there is a gettoken parameter)
 692                 if ( isset( $moduleParams['gettoken'] ) ) {
 693                         $gettoken = $moduleParams['gettoken'];
 694                 } else {
 695                         $gettoken = false;
 696                 }
 697
 698                 $salt = $module->getTokenSalt();
 699                 if ( $salt !== false && !$gettoken ) {
 700                         if ( !isset( $moduleParams['token'] ) ) {
 701                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 702                         } else {
 703                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 704                                         $this->dieUsageMsg( 'sessionfailure' );
 705                                 }
 706                         }
 707                 }
 708                 return $module;
 709         }
 710
 711         /**
 712          * Check the max lag if necessary
 713          * @param $module ApiBase object: Api module being used
 714          * @param $params Array an array containing the request parameters.
 715          * @return boolean True on success, false should exit immediately
 716          */
 717         protected function checkMaxLag( $module, $params ) {
 718                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 719                         // Check for maxlag
 720                         global $wgShowHostnames;
 721                         $maxLag = $params['maxlag'];
 722                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 723                         if ( $lag > $maxLag ) {
 724                                 $response = $this->getRequest()->response();
 725
 726                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 727                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 728
 729                                 if ( $wgShowHostnames ) {
 730                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 731                                 } else {
 732                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 733                                 }
 734                                 return false;
 735                         }
 736                 }
 737                 return true;
 738         }
 739
 740         /**
 741          * Check for sufficient permissions to execute
 742          * @param $module ApiBase An Api module
 743          */
 744         protected function checkExecutePermissions( $module ) {
 745                 $user = $this->getUser();
 746                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 747                         !$user->isAllowed( 'read' ) )
 748                 {
 749                         $this->dieUsageMsg( 'readrequired' );
 750                 }
 751                 if ( $module->isWriteMode() ) {
 752                         if ( !$this->mEnableWrite ) {
 753                                 $this->dieUsageMsg( 'writedisabled' );
 754                         }
 755                         if ( !$user->isAllowed( 'writeapi' ) ) {
 756                                 $this->dieUsageMsg( 'writerequired' );
 757                         }
 758                         if ( wfReadOnly() ) {
 759                                 $this->dieReadOnly();
 760                         }
 761                 }
 762         }
 763
 764         /**
 765          * Check POST for external response and setup result printer
 766          * @param $module ApiBase An Api module
 767          * @param $params Array an array with the request parameters
 768          */
 769         protected function setupExternalResponse( $module, $params ) {
 770                 // Ignore mustBePosted() for internal calls
 771                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 772                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 773                 }
 774
 775                 // See if custom printer is used
 776                 $this->mPrinter = $module->getCustomPrinter();
 777                 if ( is_null( $this->mPrinter ) ) {
 778                         // Create an appropriate printer
 779                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 780                 }
 781
 782                 if ( $this->mPrinter->getNeedsRawData() ) {
 783                         $this->getResult()->setRawMode();
 784                 }
 785         }
 786
 787         /**
 788          * Execute the actual module, without any error handling
 789          */
 790         protected function executeAction() {
 791                 $params = $this->setupExecuteAction();
 792                 $module = $this->setupModule();
 793
 794                 $this->checkExecutePermissions( $module );
 795
 796                 if ( !$this->checkMaxLag( $module, $params ) ) {
 797                         return;
 798                 }
 799
 800                 if ( !$this->mInternalMode ) {
 801                         $this->setupExternalResponse( $module, $params );
 802                 }
 803
 804                 // Execute
 805                 $module->profileIn();
 806                 $module->execute();
 807                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 808                 $module->profileOut();
 809
 810                 if ( !$this->mInternalMode ) {
 811                         //append Debug information
 812                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 813
 814                         // Print result data
 815                         $this->printResult( false );
 816                 }
 817         }
 818
 819         /**
 820          * Print results using the current printer
 821          *
 822          * @param $isError bool
 823          */
 824         protected function printResult( $isError ) {
 825                 $this->getResult()->cleanUpUTF8();
 826                 $printer = $this->mPrinter;
 827                 $printer->profileIn();
 828
 829                 /**
 830                  * If the help message is requested in the default (xmlfm) format,
 831                  * tell the printer not to escape ampersands so that our links do
 832                  * not break.
 833                  */
 834                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 835                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 836
 837                 $printer->initPrinter( $isError );
 838
 839                 $printer->execute();
 840                 $printer->closePrinter();
 841                 $printer->profileOut();
 842         }
 843
 844         /**
 845          * @return bool
 846          */
 847         public function isReadMode() {
 848                 return false;
 849         }
 850
 851         /**
 852          * See ApiBase for description.
 853          *
 854          * @return array
 855          */
 856         public function getAllowedParams() {
 857                 return array(
 858                         'format' => array(
 859                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 860                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 861                         ),
 862                         'action' => array(
 863                                 ApiBase::PARAM_DFLT => 'help',
 864                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 865                         ),
 866                         'version' => false,
 867                         'maxlag'  => array(
 868                                 ApiBase::PARAM_TYPE => 'integer'
 869                         ),
 870                         'smaxage' => array(
 871                                 ApiBase::PARAM_TYPE => 'integer',
 872                                 ApiBase::PARAM_DFLT => 0
 873                         ),
 874                         'maxage' => array(
 875                                 ApiBase::PARAM_TYPE => 'integer',
 876                                 ApiBase::PARAM_DFLT => 0
 877                         ),
 878                         'requestid' => null,
 879                         'servedby'  => false,
 880                         'origin' => null,
 881                 );
 882         }
 883
 884         /**
 885          * See ApiBase for description.
 886          *
 887          * @return array
 888          */
 889         public function getParamDescription() {
 890                 return array(
 891                         'format' => 'The format of the output',
 892                         'action' => 'What action you would like to perform. See below for module help',
 893                         'version' => 'When showing help, include version for each module',
 894                         'maxlag' => array(
 895                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 896                                 'To save actions causing any more site replication lag, this parameter can make the client',
 897                                 'wait until the replication lag is less than the specified value.',
 898                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 899                                 '"Waiting for $host: $lag seconds lagged\n".',
 900                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 901                         ),
 902                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 903                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 904                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 905                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 906                         'origin' => array(
 907                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
 908                                 '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 .',
 909                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
 910                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
 911                         ),
 912                 );
 913         }
 914
 915         /**
 916          * See ApiBase for description.
 917          *
 918          * @return array
 919          */
 920         public function getDescription() {
 921                 return array(
 922                         '',
 923                         '',
 924                         '**********************************************************************************************************',
 925                         '**                                                                                                      **',
 926                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 927                         '**                                                                                                      **',
 928                         '**                                     Documentation and Examples:                                      **',
 929                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 930                         '**                                                                                                      **',
 931                         '**********************************************************************************************************',
 932                         '',
 933                         'Status:                All features shown on this page should be working, but the API',
 934                         '                       is still in active development, and may change at any time.',
 935                         '                       Make sure to monitor our mailing list for any updates',
 936                         '',
 937                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 938                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 939                         '                       header and the error code sent back will be set to the same value',
 940                         '',
 941                         '                       In the case of an invalid action being passed, these will have a value',
 942                         '                       of "unknown_action"',
 943                         '',
 944                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 945                         '',
 946                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 947                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 948                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 949                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 950                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 951                         '',
 952                         '',
 953                         '',
 954                         '',
 955                         '',
 956                 );
 957         }
 958
 959         /**
 960          * @return array
 961          */
 962         public function getPossibleErrors() {
 963                 return array_merge( parent::getPossibleErrors(), array(
 964                         array( 'readonlytext' ),
 965                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 966                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 967                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 968                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 969                 ) );
 970         }
 971
 972         /**
 973          * Returns an array of strings with credits for the API
 974          * @return array
 975          */
 976         protected function getCredits() {
 977                 return array(
 978                         'API developers:',
 979                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
 980                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 981                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 982                         '    Sam Reed - sam @ reedyboy . net',
 983                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
 984                         '',
 985                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 986                         'or file a bug report at https://bugzilla.wikimedia.org/'
 987                 );
 988         }
 989
 990         /**
 991          * Sets whether the pretty-printer should format *bold* and $italics$
 992          *
 993          * @param $help bool
 994          */
 995         public function setHelp( $help = true ) {
 996                 $this->mPrinter->setHelp( $help );
 997         }
 998
 999         /**
1000          * Override the parent to generate help messages for all available modules.
1001          *
1002          * @return string
1003          */
1004         public function makeHelpMsg() {
1005                 global $wgMemc, $wgAPICacheHelpTimeout;
1006                 $this->setHelp();
1007                 // Get help text from cache if present
1008                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1009                         SpecialVersion::getVersion( 'nodb' ) .
1010                         $this->getShowVersions() );
1011                 if ( $wgAPICacheHelpTimeout > 0 ) {
1012                         $cached = $wgMemc->get( $key );
1013                         if ( $cached ) {
1014                                 return $cached;
1015                         }
1016                 }
1017                 $retval = $this->reallyMakeHelpMsg();
1018                 if ( $wgAPICacheHelpTimeout > 0 ) {
1019                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1020                 }
1021                 return $retval;
1022         }
1023
1024         /**
1025          * @return mixed|string
1026          */
1027         public function reallyMakeHelpMsg() {
1028                 $this->setHelp();
1029
1030                 // Use parent to make default message for the main module
1031                 $msg = parent::makeHelpMsg();
1032
1033                 $astriks = str_repeat( '*** ', 14 );
1034                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1035                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1036                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1037                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1038                         $msg2 = $module->makeHelpMsg();
1039                         if ( $msg2 !== false ) {
1040                                 $msg .= $msg2;
1041                         }
1042                         $msg .= "\n";
1043                 }
1044
1045                 $msg .= "\n$astriks Permissions $astriks\n\n";
1046                 foreach ( self::$mRights as $right => $rightMsg ) {
1047                         $groups = User::getGroupsWithPermission( $right );
1048                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
1049                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1050
1051                 }
1052
1053                 $msg .= "\n$astriks Formats  $astriks\n\n";
1054                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1055                         $module = $this->createPrinterByName( $formatName );
1056                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1057                         $msg2 = $module->makeHelpMsg();
1058                         if ( $msg2 !== false ) {
1059                                 $msg .= $msg2;
1060                         }
1061                         $msg .= "\n";
1062                 }
1063
1064                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1065
1066                 return $msg;
1067         }
1068
1069         /**
1070          * @param $module ApiBase
1071          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1072          * @return string
1073          */
1074         public static function makeHelpMsgHeader( $module, $paramName ) {
1075                 $modulePrefix = $module->getModulePrefix();
1076                 if ( strval( $modulePrefix ) !== '' ) {
1077                         $modulePrefix = "($modulePrefix) ";
1078                 }
1079
1080                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1081         }
1082
1083         private $mCanApiHighLimits = null;
1084
1085         /**
1086          * Check whether the current user is allowed to use high limits
1087          * @return bool
1088          */
1089         public function canApiHighLimits() {
1090                 if ( !isset( $this->mCanApiHighLimits ) ) {
1091                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1092                 }
1093
1094                 return $this->mCanApiHighLimits;
1095         }
1096
1097         /**
1098          * Check whether the user wants us to show version information in the API help
1099          * @return bool
1100          */
1101         public function getShowVersions() {
1102                 return $this->mShowVersions;
1103         }
1104
1105         /**
1106          * Returns the version information of this file, plus it includes
1107          * the versions for all files that are not callable proper API modules
1108          *
1109          * @return array
1110          */
1111         public function getVersion() {
1112                 $vers = array();
1113                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1114                 $vers[] = __CLASS__ . ': $Id$';
1115                 $vers[] = ApiBase::getBaseVersion();
1116                 $vers[] = ApiFormatBase::getBaseVersion();
1117                 $vers[] = ApiQueryBase::getBaseVersion();
1118                 return $vers;
1119         }
1120
1121         /**
1122          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1123          * classes who wish to add their own modules to their lexicon or override the
1124          * behavior of inherent ones.
1125          *
1126          * @param $mdlName String The identifier for this module.
1127          * @param $mdlClass String The class where this module is implemented.
1128          */
1129         protected function addModule( $mdlName, $mdlClass ) {
1130                 $this->mModules[$mdlName] = $mdlClass;
1131         }
1132
1133         /**
1134          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1135          * classes who wish to add to or modify current formatters.
1136          *
1137          * @param $fmtName string The identifier for this format.
1138          * @param $fmtClass ApiFormatBase The class implementing this format.
1139          */
1140         protected function addFormat( $fmtName, $fmtClass ) {
1141                 $this->mFormats[$fmtName] = $fmtClass;
1142         }
1143
1144         /**
1145          * Get the array mapping module names to class names
1146          * @return array
1147          */
1148         function getModules() {
1149                 return $this->mModules;
1150         }
1151
1152         /**
1153          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1154          *
1155          * @since 1.18
1156          * @return array
1157          */
1158         public function getFormats() {
1159                 return $this->mFormats;
1160         }
1161 }
1162
1163 /**
1164  * This exception will be thrown when dieUsage is called to stop module execution.
1165  * The exception handling code will print a help screen explaining how this API may be used.
1166  *
1167  * @ingroup API
1168  */
1169 class UsageException extends MWException {
1170
1171         private $mCodestr;
1172
1173         /**
1174          * @var null|array
1175          */
1176         private $mExtraData;
1177
1178         /**
1179          * @param $message string
1180          * @param $codestr string
1181          * @param $code int
1182          * @param $extradata array|null
1183          */
1184         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1185                 parent::__construct( $message, $code );
1186                 $this->mCodestr = $codestr;
1187                 $this->mExtraData = $extradata;
1188         }
1189
1190         /**
1191          * @return string
1192          */
1193         public function getCodeString() {
1194                 return $this->mCodestr;
1195         }
1196
1197         /**
1198          * @return array
1199          */
1200         public function getMessageArray() {
1201                 $result = array(
1202                         'code' => $this->mCodestr,
1203                         'info' => $this->getMessage()
1204                 );
1205                 if ( is_array( $this->mExtraData ) ) {
1206                         $result = array_merge( $result, $this->mExtraData );
1207                 }
1208                 return $result;
1209         }
1210
1211         /**
1212          * @return string
1213          */
1214         public function __toString() {
1215                 return "{$this->getCodeString()}: {$this->getMessage()}";
1216         }
1217 }