includes/MediaWiki.php

   1 <?php
   2 /**
   3  * Helper class for the index.php entry point.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Logger\LoggerFactory;
  24 use Psr\Log\LoggerInterface;
  25 use MediaWiki\MediaWikiServices;
  26 use Wikimedia\Rdbms\ILBFactory;
  27 use Wikimedia\Rdbms\ChronologyProtector;
  28 use Wikimedia\Rdbms\DBConnectionError;
  29 use Liuggio\StatsdClient\Sender\SocketSender;
  30
  31 /**
  32  * The MediaWiki class is the helper class for the index.php entry point.
  33  */
  34 class MediaWiki {
  35         /**
  36          * @var IContextSource
  37          */
  38         private $context;
  39
  40         /**
  41          * @var Config
  42          */
  43         private $config;
  44
  45         /**
  46          * @var string Cache what action this request is
  47          */
  48         private $action;
  49
  50         /**
  51          * @param IContextSource|null $context
  52          */
  53         public function __construct( IContextSource $context = null ) {
  54                 if ( !$context ) {
  55                         $context = RequestContext::getMain();
  56                 }
  57
  58                 $this->context = $context;
  59                 $this->config = $context->getConfig();
  60         }
  61
  62         /**
  63          * Parse the request to get the Title object
  64          *
  65          * @throws MalformedTitleException If a title has been provided by the user, but is invalid.
  66          * @return Title Title object to be $wgTitle
  67          */
  68         private function parseTitle() {
  69                 $request = $this->context->getRequest();
  70                 $curid = $request->getInt( 'curid' );
  71                 $title = $request->getVal( 'title' );
  72                 $action = $request->getVal( 'action' );
  73
  74                 if ( $request->getCheck( 'search' ) ) {
  75                         // Compatibility with old search URLs which didn't use Special:Search
  76                         // Just check for presence here, so blank requests still
  77                         // show the search page when using ugly URLs (T10054).
  78                         $ret = SpecialPage::getTitleFor( 'Search' );
  79                 } elseif ( $curid ) {
  80                         // URLs like this are generated by RC, because rc_title isn't always accurate
  81                         $ret = Title::newFromID( $curid );
  82                 } else {
  83                         $ret = Title::newFromURL( $title );
  84                         // Alias NS_MEDIA page URLs to NS_FILE...we only use NS_MEDIA
  85                         // in wikitext links to tell Parser to make a direct file link
  86                         if ( !is_null( $ret ) && $ret->getNamespace() == NS_MEDIA ) {
  87                                 $ret = Title::makeTitle( NS_FILE, $ret->getDBkey() );
  88                         }
  89                         $contLang = MediaWikiServices::getInstance()->getContentLanguage();
  90                         // Check variant links so that interwiki links don't have to worry
  91                         // about the possible different language variants
  92                         if (
  93                                 $contLang->hasVariants() && !is_null( $ret ) && $ret->getArticleID() == 0
  94                         ) {
  95                                 $contLang->findVariantLink( $title, $ret );
  96                         }
  97                 }
  98
  99                 // If title is not provided, always allow oldid and diff to set the title.
 100                 // If title is provided, allow oldid and diff to override the title, unless
 101                 // we are talking about a special page which might use these parameters for
 102                 // other purposes.
 103                 if ( $ret === null || !$ret->isSpecialPage() ) {
 104                         // We can have urls with just ?diff=,?oldid= or even just ?diff=
 105                         $oldid = $request->getInt( 'oldid' );
 106                         $oldid = $oldid ?: $request->getInt( 'diff' );
 107                         // Allow oldid to override a changed or missing title
 108                         if ( $oldid ) {
 109                                 $rev = Revision::newFromId( $oldid );
 110                                 $ret = $rev ? $rev->getTitle() : $ret;
 111                         }
 112                 }
 113
 114                 // Use the main page as default title if nothing else has been provided
 115                 if ( $ret === null
 116                         && strval( $title ) === ''
 117                         && !$request->getCheck( 'curid' )
 118                         && $action !== 'delete'
 119                 ) {
 120                         $ret = Title::newMainPage();
 121                 }
 122
 123                 if ( $ret === null || ( $ret->getDBkey() == '' && !$ret->isExternal() ) ) {
 124                         // If we get here, we definitely don't have a valid title; throw an exception.
 125                         // Try to get detailed invalid title exception first, fall back to MalformedTitleException.
 126                         Title::newFromTextThrow( $title );
 127                         throw new MalformedTitleException( 'badtitletext', $title );
 128                 }
 129
 130                 return $ret;
 131         }
 132
 133         /**
 134          * Get the Title object that we'll be acting on, as specified in the WebRequest
 135          * @return Title
 136          */
 137         public function getTitle() {
 138                 if ( !$this->context->hasTitle() ) {
 139                         try {
 140                                 $this->context->setTitle( $this->parseTitle() );
 141                         } catch ( MalformedTitleException $ex ) {
 142                                 $this->context->setTitle( SpecialPage::getTitleFor( 'Badtitle' ) );
 143                         }
 144                 }
 145                 return $this->context->getTitle();
 146         }
 147
 148         /**
 149          * Returns the name of the action that will be executed.
 150          *
 151          * @return string Action
 152          */
 153         public function getAction() {
 154                 if ( $this->action === null ) {
 155                         $this->action = Action::getActionName( $this->context );
 156                 }
 157
 158                 return $this->action;
 159         }
 160
 161         /**
 162          * Performs the request.
 163          * - bad titles
 164          * - read restriction
 165          * - local interwiki redirects
 166          * - redirect loop
 167          * - special pages
 168          * - normal pages
 169          *
 170          * @throws MWException|PermissionsError|BadTitleError|HttpError
 171          * @return void
 172          */
 173         private function performRequest() {
 174                 global $wgTitle;
 175
 176                 $request = $this->context->getRequest();
 177                 $requestTitle = $title = $this->context->getTitle();
 178                 $output = $this->context->getOutput();
 179                 $user = $this->context->getUser();
 180
 181                 if ( $request->getVal( 'printable' ) === 'yes' ) {
 182                         $output->setPrintable();
 183                 }
 184
 185                 $unused = null; // To pass it by reference
 186                 Hooks::run( 'BeforeInitialize', [ &$title, &$unused, &$output, &$user, $request, $this ] );
 187
 188                 // Invalid titles. T23776: The interwikis must redirect even if the page name is empty.
 189                 if ( is_null( $title ) || ( $title->getDBkey() == '' && !$title->isExternal() )
 190                         || $title->isSpecial( 'Badtitle' )
 191                 ) {
 192                         $this->context->setTitle( SpecialPage::getTitleFor( 'Badtitle' ) );
 193                         try {
 194                                 $this->parseTitle();
 195                         } catch ( MalformedTitleException $ex ) {
 196                                 throw new BadTitleError( $ex );
 197                         }
 198                         throw new BadTitleError();
 199                 }
 200
 201                 // Check user's permissions to read this page.
 202                 // We have to check here to catch special pages etc.
 203                 // We will check again in Article::view().
 204                 $permErrors = $title->isSpecial( 'RunJobs' )
 205                         ? [] // relies on HMAC key signature alone
 206                         : $title->getUserPermissionsErrors( 'read', $user );
 207                 if ( count( $permErrors ) ) {
 208                         // T34276: allowing the skin to generate output with $wgTitle or
 209                         // $this->context->title set to the input title would allow anonymous users to
 210                         // determine whether a page exists, potentially leaking private data. In fact, the
 211                         // curid and oldid request  parameters would allow page titles to be enumerated even
 212                         // when they are not guessable. So we reset the title to Special:Badtitle before the
 213                         // permissions error is displayed.
 214
 215                         // The skin mostly uses $this->context->getTitle() these days, but some extensions
 216                         // still use $wgTitle.
 217                         $badTitle = SpecialPage::getTitleFor( 'Badtitle' );
 218                         $this->context->setTitle( $badTitle );
 219                         $wgTitle = $badTitle;
 220
 221                         throw new PermissionsError( 'read', $permErrors );
 222                 }
 223
 224                 // Interwiki redirects
 225                 if ( $title->isExternal() ) {
 226                         $rdfrom = $request->getVal( 'rdfrom' );
 227                         if ( $rdfrom ) {
 228                                 $url = $title->getFullURL( [ 'rdfrom' => $rdfrom ] );
 229                         } else {
 230                                 $query = $request->getValues();
 231                                 unset( $query['title'] );
 232                                 $url = $title->getFullURL( $query );
 233                         }
 234                         // Check for a redirect loop
 235                         if ( !preg_match( '/^' . preg_quote( $this->config->get( 'Server' ), '/' ) . '/', $url )
 236                                 && $title->isLocal()
 237                         ) {
 238                                 // 301 so google et al report the target as the actual url.
 239                                 $output->redirect( $url, 301 );
 240                         } else {
 241                                 $this->context->setTitle( SpecialPage::getTitleFor( 'Badtitle' ) );
 242                                 try {
 243                                         $this->parseTitle();
 244                                 } catch ( MalformedTitleException $ex ) {
 245                                         throw new BadTitleError( $ex );
 246                                 }
 247                                 throw new BadTitleError();
 248                         }
 249                 // Handle any other redirects.
 250                 // Redirect loops, titleless URL, $wgUsePathInfo URLs, and URLs with a variant
 251                 } elseif ( !$this->tryNormaliseRedirect( $title ) ) {
 252                         // Prevent information leak via Special:MyPage et al (T109724)
 253                         $spFactory = MediaWikiServices::getInstance()->getSpecialPageFactory();
 254                         if ( $title->isSpecialPage() ) {
 255                                 $specialPage = $spFactory->getPage( $title->getDBkey() );
 256                                 if ( $specialPage instanceof RedirectSpecialPage ) {
 257                                         $specialPage->setContext( $this->context );
 258                                         if ( $this->config->get( 'HideIdentifiableRedirects' )
 259                                                 && $specialPage->personallyIdentifiableTarget()
 260                                         ) {
 261                                                 list( , $subpage ) = $spFactory->resolveAlias( $title->getDBkey() );
 262                                                 $target = $specialPage->getRedirect( $subpage );
 263                                                 // Target can also be true. We let that case fall through to normal processing.
 264                                                 if ( $target instanceof Title ) {
 265                                                         if ( $target->isExternal() ) {
 266                                                                 // Handle interwiki redirects
 267                                                                 $target = SpecialPage::getTitleFor(
 268                                                                         'GoToInterwiki',
 269                                                                         'force/' . $target->getPrefixedDBkey()
 270                                                                 );
 271                                                         }
 272
 273                                                         $query = $specialPage->getRedirectQuery( $subpage ) ?: [];
 274                                                         $request = new DerivativeRequest( $this->context->getRequest(), $query );
 275                                                         $request->setRequestURL( $this->context->getRequest()->getRequestURL() );
 276                                                         $this->context->setRequest( $request );
 277                                                         // Do not varnish cache these. May vary even for anons
 278                                                         $this->context->getOutput()->lowerCdnMaxage( 0 );
 279                                                         $this->context->setTitle( $target );
 280                                                         $wgTitle = $target;
 281                                                         // Reset action type cache. (Special pages have only view)
 282                                                         $this->action = null;
 283                                                         $title = $target;
 284                                                         $output->addJsConfigVars( [
 285                                                                 'wgInternalRedirectTargetUrl' => $target->getFullURL( $query ),
 286                                                         ] );
 287                                                         $output->addModules( 'mediawiki.action.view.redirect' );
 288                                                 }
 289                                         }
 290                                 }
 291                         }
 292
 293                         // Special pages ($title may have changed since if statement above)
 294                         if ( $title->isSpecialPage() ) {
 295                                 // Actions that need to be made when we have a special pages
 296                                 $spFactory->executePath( $title, $this->context );
 297                         } else {
 298                                 // ...otherwise treat it as an article view. The article
 299                                 // may still be a wikipage redirect to another article or URL.
 300                                 $article = $this->initializeArticle();
 301                                 if ( is_object( $article ) ) {
 302                                         $this->performAction( $article, $requestTitle );
 303                                 } elseif ( is_string( $article ) ) {
 304                                         $output->redirect( $article );
 305                                 } else {
 306                                         throw new MWException( "Shouldn't happen: MediaWiki::initializeArticle()"
 307                                                 . " returned neither an object nor a URL" );
 308                                 }
 309                         }
 310                 }
 311         }
 312
 313         /**
 314          * Handle redirects for uncanonical title requests.
 315          *
 316          * Handles:
 317          * - Redirect loops.
 318          * - No title in URL.
 319          * - $wgUsePathInfo URLs.
 320          * - URLs with a variant.
 321          * - Other non-standard URLs (as long as they have no extra query parameters).
 322          *
 323          * Behaviour:
 324          * - Normalise title values:
 325          *   /wiki/Foo%20Bar -> /wiki/Foo_Bar
 326          * - Normalise empty title:
 327          *   /wiki/ -> /wiki/Main
 328          *   /w/index.php?title= -> /wiki/Main
 329          * - Don't redirect anything with query parameters other than 'title' or 'action=view'.
 330          *
 331          * @param Title $title
 332          * @return bool True if a redirect was set.
 333          * @throws HttpError
 334          */
 335         private function tryNormaliseRedirect( Title $title ) {
 336                 $request = $this->context->getRequest();
 337                 $output = $this->context->getOutput();
 338
 339                 if ( $request->getVal( 'action', 'view' ) != 'view'
 340                         || $request->wasPosted()
 341                         || ( $request->getCheck( 'title' )
 342                                 && $title->getPrefixedDBkey() == $request->getVal( 'title' ) )
 343                         || count( $request->getValueNames( [ 'action', 'title' ] ) )
 344                         || !Hooks::run( 'TestCanonicalRedirect', [ $request, $title, $output ] )
 345                 ) {
 346                         return false;
 347                 }
 348
 349                 if ( $this->config->get( 'MainPageIsDomainRoot' ) && $request->getRequestURL() === '/' ) {
 350                         return false;
 351                 }
 352
 353                 if ( $title->isSpecialPage() ) {
 354                         list( $name, $subpage ) = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 355                                 resolveAlias( $title->getDBkey() );
 356                         if ( $name ) {
 357                                 $title = SpecialPage::getTitleFor( $name, $subpage );
 358                         }
 359                 }
 360                 // Redirect to canonical url, make it a 301 to allow caching
 361                 $targetUrl = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
 362                 if ( $targetUrl == $request->getFullRequestURL() ) {
 363                         $message = "Redirect loop detected!\n\n" .
 364                                 "This means the wiki got confused about what page was " .
 365                                 "requested; this sometimes happens when moving a wiki " .
 366                                 "to a new server or changing the server configuration.\n\n";
 367
 368                         if ( $this->config->get( 'UsePathInfo' ) ) {
 369                                 $message .= "The wiki is trying to interpret the page " .
 370                                         "title from the URL path portion (PATH_INFO), which " .
 371                                         "sometimes fails depending on the web server. Try " .
 372                                         "setting \"\$wgUsePathInfo = false;\" in your " .
 373                                         "LocalSettings.php, or check that \$wgArticlePath " .
 374                                         "is correct.";
 375                         } else {
 376                                 $message .= "Your web server was detected as possibly not " .
 377                                         "supporting URL path components (PATH_INFO) correctly; " .
 378                                         "check your LocalSettings.php for a customized " .
 379                                         "\$wgArticlePath setting and/or toggle \$wgUsePathInfo " .
 380                                         "to true.";
 381                         }
 382                         throw new HttpError( 500, $message );
 383                 }
 384                 $output->setCdnMaxage( 1200 );
 385                 $output->redirect( $targetUrl, '301' );
 386                 return true;
 387         }
 388
 389         /**
 390          * Initialize the main Article object for "standard" actions (view, etc)
 391          * Create an Article object for the page, following redirects if needed.
 392          *
 393          * @return Article|string An Article, or a string to redirect to another URL
 394          */
 395         private function initializeArticle() {
 396                 $title = $this->context->getTitle();
 397                 if ( $this->context->canUseWikiPage() ) {
 398                         // Try to use request context wiki page, as there
 399                         // is already data from db saved in per process
 400                         // cache there from this->getAction() call.
 401                         $page = $this->context->getWikiPage();
 402                 } else {
 403                         // This case should not happen, but just in case.
 404                         // @TODO: remove this or use an exception
 405                         $page = WikiPage::factory( $title );
 406                         $this->context->setWikiPage( $page );
 407                         wfWarn( "RequestContext::canUseWikiPage() returned false" );
 408                 }
 409
 410                 // Make GUI wrapper for the WikiPage
 411                 $article = Article::newFromWikiPage( $page, $this->context );
 412
 413                 // Skip some unnecessary code if the content model doesn't support redirects
 414                 if ( !ContentHandler::getForTitle( $title )->supportsRedirects() ) {
 415                         return $article;
 416                 }
 417
 418                 $request = $this->context->getRequest();
 419
 420                 // Namespace might change when using redirects
 421                 // Check for redirects ...
 422                 $action = $request->getVal( 'action', 'view' );
 423                 $file = ( $page instanceof WikiFilePage ) ? $page->getFile() : null;
 424                 if ( ( $action == 'view' || $action == 'render' ) // ... for actions that show content
 425                         && !$request->getVal( 'oldid' ) // ... and are not old revisions
 426                         && !$request->getVal( 'diff' ) // ... and not when showing diff
 427                         && $request->getVal( 'redirect' ) != 'no' // ... unless explicitly told not to
 428                         // ... and the article is not a non-redirect image page with associated file
 429                         && !( is_object( $file ) && $file->exists() && !$file->getRedirected() )
 430                 ) {
 431                         // Give extensions a change to ignore/handle redirects as needed
 432                         $ignoreRedirect = $target = false;
 433
 434                         Hooks::run( 'InitializeArticleMaybeRedirect',
 435                                 [ &$title, &$request, &$ignoreRedirect, &$target, &$article ] );
 436                         $page = $article->getPage(); // reflect any hook changes
 437
 438                         // Follow redirects only for... redirects.
 439                         // If $target is set, then a hook wanted to redirect.
 440                         if ( !$ignoreRedirect && ( $target || $page->isRedirect() ) ) {
 441                                 // Is the target already set by an extension?
 442                                 $target = $target ?: $page->followRedirect();
 443                                 if ( is_string( $target ) && !$this->config->get( 'DisableHardRedirects' ) ) {
 444                                         // we'll need to redirect
 445                                         return $target;
 446                                 }
 447                                 if ( is_object( $target ) ) {
 448                                         // Rewrite environment to redirected article
 449                                         $rpage = WikiPage::factory( $target );
 450                                         $rpage->loadPageData();
 451                                         if ( $rpage->exists() || ( is_object( $file ) && !$file->isLocal() ) ) {
 452                                                 $rarticle = Article::newFromWikiPage( $rpage, $this->context );
 453                                                 $rarticle->setRedirectedFrom( $title );
 454
 455                                                 $article = $rarticle;
 456                                                 $this->context->setTitle( $target );
 457                                                 $this->context->setWikiPage( $article->getPage() );
 458                                         }
 459                                 }
 460                         } else {
 461                                 // Article may have been changed by hook
 462                                 $this->context->setTitle( $article->getTitle() );
 463                                 $this->context->setWikiPage( $article->getPage() );
 464                         }
 465                 }
 466
 467                 return $article;
 468         }
 469
 470         /**
 471          * Perform one of the "standard" actions
 472          *
 473          * @param Page $page
 474          * @param Title $requestTitle The original title, before any redirects were applied
 475          */
 476         private function performAction( Page $page, Title $requestTitle ) {
 477                 $request = $this->context->getRequest();
 478                 $output = $this->context->getOutput();
 479                 $title = $this->context->getTitle();
 480                 $user = $this->context->getUser();
 481
 482                 if ( !Hooks::run( 'MediaWikiPerformAction',
 483                                 [ $output, $page, $title, $user, $request, $this ] )
 484                 ) {
 485                         return;
 486                 }
 487
 488                 $act = $this->getAction();
 489                 $action = Action::factory( $act, $page, $this->context );
 490
 491                 if ( $action instanceof Action ) {
 492                         // Narrow DB query expectations for this HTTP request
 493                         $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 494                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 495                         if ( $request->wasPosted() && !$action->doesWrites() ) {
 496                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 497                                 $request->markAsSafeRequest();
 498                         }
 499
 500                         # Let CDN cache things if we can purge them.
 501                         if ( $this->config->get( 'UseCdn' ) &&
 502                                 in_array(
 503                                         // Use PROTO_INTERNAL because that's what getCdnUrls() uses
 504                                         wfExpandUrl( $request->getRequestURL(), PROTO_INTERNAL ),
 505                                         $requestTitle->getCdnUrls()
 506                                 )
 507                         ) {
 508                                 $output->setCdnMaxage( $this->config->get( 'CdnMaxAge' ) );
 509                         }
 510
 511                         $action->show();
 512                         return;
 513                 }
 514
 515                 // If we've not found out which action it is by now, it's unknown
 516                 $output->setStatusCode( 404 );
 517                 $output->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
 518         }
 519
 520         /**
 521          * Run the current MediaWiki instance; index.php just calls this
 522          */
 523         public function run() {
 524                 try {
 525                         $this->setDBProfilingAgent();
 526                         try {
 527                                 $this->main();
 528                         } catch ( ErrorPageError $e ) {
 529                                 // T64091: while exceptions are convenient to bubble up GUI errors,
 530                                 // they are not internal application faults. As with normal requests, this
 531                                 // should commit, print the output, do deferred updates, jobs, and profiling.
 532                                 $this->doPreOutputCommit();
 533                                 $e->report(); // display the GUI error
 534                         }
 535                 } catch ( Exception $e ) {
 536                         $context = $this->context;
 537                         $action = $context->getRequest()->getVal( 'action', 'view' );
 538                         if (
 539                                 $e instanceof DBConnectionError &&
 540                                 $context->hasTitle() &&
 541                                 $context->getTitle()->canExist() &&
 542                                 in_array( $action, [ 'view', 'history' ], true ) &&
 543                                 HTMLFileCache::useFileCache( $this->context, HTMLFileCache::MODE_OUTAGE )
 544                         ) {
 545                                 // Try to use any (even stale) file during outages...
 546                                 $cache = new HTMLFileCache( $context->getTitle(), $action );
 547                                 if ( $cache->isCached() ) {
 548                                         $cache->loadFromFileCache( $context, HTMLFileCache::MODE_OUTAGE );
 549                                         print MWExceptionRenderer::getHTML( $e );
 550                                         exit;
 551                                 }
 552                         }
 553
 554                         MWExceptionHandler::handleException( $e );
 555                 } catch ( Error $e ) {
 556                         // Type errors and such: at least handle it now and clean up the LBFactory state
 557                         MWExceptionHandler::handleException( $e );
 558                 }
 559
 560                 $this->doPostOutputShutdown( 'normal' );
 561         }
 562
 563         private function setDBProfilingAgent() {
 564                 $services = MediaWikiServices::getInstance();
 565                 // Add a comment for easy SHOW PROCESSLIST interpretation
 566                 $name = $this->context->getUser()->getName();
 567                 $services->getDBLoadBalancerFactory()->setAgentName(
 568                         mb_strlen( $name ) > 15 ? mb_substr( $name, 0, 15 ) . '...' : $name
 569                 );
 570         }
 571
 572         /**
 573          * @see MediaWiki::preOutputCommit()
 574          * @param callable|null $postCommitWork [default: null]
 575          * @since 1.26
 576          */
 577         public function doPreOutputCommit( callable $postCommitWork = null ) {
 578                 self::preOutputCommit( $this->context, $postCommitWork );
 579         }
 580
 581         /**
 582          * This function commits all DB and session changes as needed *before* the
 583          * client can receive a response (in case DB commit fails) and thus also before
 584          * the response can trigger a subsequent related request by the client
 585          *
 586          * If there is a significant amount of content to flush, it can be done in $postCommitWork
 587          *
 588          * @param IContextSource $context
 589          * @param callable|null $postCommitWork [default: null]
 590          * @since 1.27
 591          */
 592         public static function preOutputCommit(
 593                 IContextSource $context, callable $postCommitWork = null
 594         ) {
 595                 $config = $context->getConfig();
 596                 $request = $context->getRequest();
 597                 $output = $context->getOutput();
 598                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 599
 600                 // Try to make sure that all RDBMs, session, and other storage updates complete
 601                 ignore_user_abort( true );
 602
 603                 // Commit all RDBMs changes from the main transaction round
 604                 $lbFactory->commitMasterChanges(
 605                         __METHOD__,
 606                         // Abort if any transaction was too big
 607                         [ 'maxWriteDuration' => $config->get( 'MaxUserDBWriteDuration' ) ]
 608                 );
 609                 wfDebug( __METHOD__ . ': primary transaction round committed' );
 610
 611                 // Run updates that need to block the client or affect output (this is the last chance)
 612                 DeferredUpdates::doUpdates( 'run', DeferredUpdates::PRESEND );
 613                 wfDebug( __METHOD__ . ': pre-send deferred updates completed' );
 614                 // Persist the session to avoid race conditions on subsequent requests by the client
 615                 $request->getSession()->save(); // T214471
 616                 wfDebug( __METHOD__ . ': session changes committed' );
 617
 618                 // Figure out whether to wait for DB replication now or to use some method that assures
 619                 // that subsequent requests by the client will use the DB replication positions written
 620                 // during the shutdown() call below; the later requires working around replication lag
 621                 // of the store containing DB replication positions (e.g. dynomite, mcrouter).
 622                 list( $flags, $strategy ) = self::getChronProtStrategy( $lbFactory, $output );
 623                 // Record ChronologyProtector positions for DBs affected in this request at this point
 624                 $cpIndex = null;
 625                 $cpClientId = null;
 626                 $lbFactory->shutdown( $flags, $postCommitWork, $cpIndex, $cpClientId );
 627                 wfDebug( __METHOD__ . ': LBFactory shutdown completed' );
 628
 629                 $allowHeaders = !( $output->isDisabled() || headers_sent() );
 630                 if ( $cpIndex > 0 ) {
 631                         if ( $allowHeaders ) {
 632                                 $now = time();
 633                                 $expires = $now + ChronologyProtector::POSITION_COOKIE_TTL;
 634                                 $options = [ 'prefix' => '' ];
 635                                 $value = $lbFactory::makeCookieValueFromCPIndex( $cpIndex, $now, $cpClientId );
 636                                 $request->response()->setCookie( 'cpPosIndex', $value, $expires, $options );
 637                         }
 638
 639                         if ( $strategy === 'cookie+url' ) {
 640                                 if ( $output->getRedirect() ) { // sanity
 641                                         $safeUrl = $lbFactory->appendShutdownCPIndexAsQuery(
 642                                                 $output->getRedirect(),
 643                                                 $cpIndex
 644                                         );
 645                                         $output->redirect( $safeUrl );
 646                                 } else {
 647                                         $e = new LogicException( "No redirect; cannot append cpPosIndex parameter." );
 648                                         MWExceptionHandler::logException( $e );
 649                                 }
 650                         }
 651                 }
 652
 653                 if ( $allowHeaders ) {
 654                         // Set a cookie to tell all CDN edge nodes to "stick" the user to the DC that
 655                         // handles this POST request (e.g. the "master" data center). Also have the user
 656                         // briefly bypass CDN so ChronologyProtector works for cacheable URLs.
 657                         if ( $request->wasPosted() && $lbFactory->hasOrMadeRecentMasterChanges() ) {
 658                                 $expires = time() + $config->get( 'DataCenterUpdateStickTTL' );
 659                                 $options = [ 'prefix' => '' ];
 660                                 $request->response()->setCookie( 'UseDC', 'master', $expires, $options );
 661                                 $request->response()->setCookie( 'UseCDNCache', 'false', $expires, $options );
 662                         }
 663
 664                         // Avoid letting a few seconds of replica DB lag cause a month of stale data.
 665                         // This logic is also intimately related to the value of $wgCdnReboundPurgeDelay.
 666                         if ( $lbFactory->laggedReplicaUsed() ) {
 667                                 $maxAge = $config->get( 'CdnMaxageLagged' );
 668                                 $output->lowerCdnMaxage( $maxAge );
 669                                 $request->response()->header( "X-Database-Lagged: true" );
 670                                 wfDebugLog( 'replication',
 671                                         "Lagged DB used; CDN cache TTL limited to $maxAge seconds" );
 672                         }
 673
 674                         // Avoid long-term cache pollution due to message cache rebuild timeouts (T133069)
 675                         if ( MessageCache::singleton()->isDisabled() ) {
 676                                 $maxAge = $config->get( 'CdnMaxageSubstitute' );
 677                                 $output->lowerCdnMaxage( $maxAge );
 678                                 $request->response()->header( "X-Response-Substitute: true" );
 679                         }
 680                 }
 681         }
 682
 683         /**
 684          * @param ILBFactory $lbFactory
 685          * @param OutputPage $output
 686          * @return array
 687          */
 688         private static function getChronProtStrategy( ILBFactory $lbFactory, OutputPage $output ) {
 689                 // Should the client return, their request should observe the new ChronologyProtector
 690                 // DB positions. This request might be on a foreign wiki domain, so synchronously update
 691                 // the DB positions in all datacenters to be safe. If this output is not a redirect,
 692                 // then OutputPage::output() will be relatively slow, meaning that running it in
 693                 // $postCommitWork should help mask the latency of those updates.
 694                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_SYNC;
 695                 $strategy = 'cookie+sync';
 696
 697                 $allowHeaders = !( $output->isDisabled() || headers_sent() );
 698                 if ( $output->getRedirect() && $lbFactory->hasOrMadeRecentMasterChanges( INF ) ) {
 699                         // OutputPage::output() will be fast, so $postCommitWork is useless for masking
 700                         // the latency of synchronously updating the DB positions in all datacenters.
 701                         // Try to make use of the time the client spends following redirects instead.
 702                         $domainDistance = self::getUrlDomainDistance( $output->getRedirect() );
 703                         if ( $domainDistance === 'local' && $allowHeaders ) {
 704                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 705                                 $strategy = 'cookie'; // use same-domain cookie and keep the URL uncluttered
 706                         } elseif ( $domainDistance === 'remote' ) {
 707                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 708                                 $strategy = 'cookie+url'; // cross-domain cookie might not work
 709                         }
 710                 }
 711
 712                 return [ $flags, $strategy ];
 713         }
 714
 715         /**
 716          * @param string $url
 717          * @return string Either "local", "remote" if in the farm, "external" otherwise
 718          */
 719         private static function getUrlDomainDistance( $url ) {
 720                 $clusterWiki = WikiMap::getWikiFromUrl( $url );
 721                 if ( WikiMap::isCurrentWikiId( $clusterWiki ) ) {
 722                         return 'local'; // the current wiki
 723                 }
 724                 if ( $clusterWiki !== false ) {
 725                         return 'remote'; // another wiki in this cluster/farm
 726                 }
 727
 728                 return 'external';
 729         }
 730
 731         /**
 732          * This function does work that can be done *after* the
 733          * user gets the HTTP response so they don't block on it
 734          *
 735          * This manages deferred updates, job insertion,
 736          * final commit, and the logging of profiling data
 737          *
 738          * @param string $mode Use 'fast' to always skip job running
 739          * @since 1.26
 740          */
 741         public function doPostOutputShutdown( $mode = 'normal' ) {
 742                 // Record backend request timing
 743                 $timing = $this->context->getTiming();
 744                 $timing->mark( 'requestShutdown' );
 745
 746                 // Perform the last synchronous operations...
 747                 try {
 748                         // Show visible profiling data if enabled (which cannot be post-send)
 749                         Profiler::instance()->logDataPageOutputOnly();
 750                 } catch ( Exception $e ) {
 751                         // An error may already have been shown in run(), so just log it to be safe
 752                         MWExceptionHandler::logException( $e );
 753                 }
 754
 755                 // Disable WebResponse setters for post-send processing (T191537).
 756                 WebResponse::disableForPostSend();
 757
 758                 $blocksHttpClient = true;
 759                 // Defer everything else if possible...
 760                 $callback = function () use ( $mode, &$blocksHttpClient ) {
 761                         try {
 762                                 $this->restInPeace( $mode, $blocksHttpClient );
 763                         } catch ( Exception $e ) {
 764                                 // If this is post-send, then displaying errors can cause broken HTML
 765                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 766                         }
 767                 };
 768
 769                 if ( function_exists( 'register_postsend_function' ) ) {
 770                         // https://github.com/facebook/hhvm/issues/1230
 771                         register_postsend_function( $callback );
 772                         /** @noinspection PhpUnusedLocalVariableInspection */
 773                         $blocksHttpClient = false;
 774                 } else {
 775                         if ( function_exists( 'fastcgi_finish_request' ) ) {
 776                                 fastcgi_finish_request();
 777                                 /** @noinspection PhpUnusedLocalVariableInspection */
 778                                 $blocksHttpClient = false;
 779                         } else {
 780                                 // Either all DB and deferred updates should happen or none.
 781                                 // The latter should not be cancelled due to client disconnect.
 782                                 ignore_user_abort( true );
 783                         }
 784
 785                         $callback();
 786                 }
 787         }
 788
 789         private function main() {
 790                 global $wgTitle;
 791
 792                 $output = $this->context->getOutput();
 793                 $request = $this->context->getRequest();
 794
 795                 // Send Ajax requests to the Ajax dispatcher.
 796                 if ( $request->getVal( 'action' ) === 'ajax' ) {
 797                         // Set a dummy title, because $wgTitle == null might break things
 798                         $title = Title::makeTitle( NS_SPECIAL, 'Badtitle/performing an AJAX call in '
 799                                 . __METHOD__
 800                         );
 801                         $this->context->setTitle( $title );
 802                         $wgTitle = $title;
 803
 804                         $dispatcher = new AjaxDispatcher( $this->config );
 805                         $dispatcher->performAction( $this->context->getUser() );
 806
 807                         return;
 808                 }
 809
 810                 // Get title from request parameters,
 811                 // is set on the fly by parseTitle the first time.
 812                 $title = $this->getTitle();
 813                 $action = $this->getAction();
 814                 $wgTitle = $title;
 815
 816                 // Set DB query expectations for this HTTP request
 817                 $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 818                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 819                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
 820                 if ( $request->hasSafeMethod() ) {
 821                         $trxProfiler->setExpectations( $trxLimits['GET'], __METHOD__ );
 822                 } else {
 823                         $trxProfiler->setExpectations( $trxLimits['POST'], __METHOD__ );
 824                 }
 825
 826                 // If the user has forceHTTPS set to true, or if the user
 827                 // is in a group requiring HTTPS, or if they have the HTTPS
 828                 // preference set, redirect them to HTTPS.
 829                 // Note: Do this after $wgTitle is setup, otherwise the hooks run from
 830                 // isLoggedIn() will do all sorts of weird stuff.
 831                 if (
 832                         $request->getProtocol() == 'http' &&
 833                         // switch to HTTPS only when supported by the server
 834                         preg_match( '#^https://#', wfExpandUrl( $request->getRequestURL(), PROTO_HTTPS ) ) &&
 835                         (
 836                                 $request->getSession()->shouldForceHTTPS() ||
 837                                 // Check the cookie manually, for paranoia
 838                                 $request->getCookie( 'forceHTTPS', '' ) ||
 839                                 // check for prefixed version that was used for a time in older MW versions
 840                                 $request->getCookie( 'forceHTTPS' ) ||
 841                                 // Avoid checking the user and groups unless it's enabled.
 842                                 (
 843                                         $this->context->getUser()->isLoggedIn()
 844                                         && $this->context->getUser()->requiresHTTPS()
 845                                 )
 846                         )
 847                 ) {
 848                         $oldUrl = $request->getFullRequestURL();
 849                         $redirUrl = preg_replace( '#^http://#', 'https://', $oldUrl );
 850
 851                         // ATTENTION: This hook is likely to be removed soon due to overall design of the system.
 852                         if ( Hooks::run( 'BeforeHttpsRedirect', [ $this->context, &$redirUrl ] ) ) {
 853                                 if ( $request->wasPosted() ) {
 854                                         // This is weird and we'd hope it almost never happens. This
 855                                         // means that a POST came in via HTTP and policy requires us
 856                                         // redirecting to HTTPS. It's likely such a request is going
 857                                         // to fail due to post data being lost, but let's try anyway
 858                                         // and just log the instance.
 859
 860                                         // @todo FIXME: See if we could issue a 307 or 308 here, need
 861                                         // to see how clients (automated & browser) behave when we do
 862                                         wfDebugLog( 'RedirectedPosts', "Redirected from HTTP to HTTPS: $oldUrl" );
 863                                 }
 864                                 // Setup dummy Title, otherwise OutputPage::redirect will fail
 865                                 $title = Title::newFromText( 'REDIR', NS_MAIN );
 866                                 $this->context->setTitle( $title );
 867                                 // Since we only do this redir to change proto, always send a vary header
 868                                 $output->addVaryHeader( 'X-Forwarded-Proto' );
 869                                 $output->redirect( $redirUrl );
 870                                 $output->output();
 871
 872                                 return;
 873                         }
 874                 }
 875
 876                 if ( $title->canExist() && HTMLFileCache::useFileCache( $this->context ) ) {
 877                         // Try low-level file cache hit
 878                         $cache = new HTMLFileCache( $title, $action );
 879                         if ( $cache->isCacheGood( /* Assume up to date */ ) ) {
 880                                 // Check incoming headers to see if client has this cached
 881                                 $timestamp = $cache->cacheTimestamp();
 882                                 if ( !$output->checkLastModified( $timestamp ) ) {
 883                                         $cache->loadFromFileCache( $this->context );
 884                                 }
 885                                 // Do any stats increment/watchlist stuff, assuming user is viewing the
 886                                 // latest revision (which should always be the case for file cache)
 887                                 $this->context->getWikiPage()->doViewUpdates( $this->context->getUser() );
 888                                 // Tell OutputPage that output is taken care of
 889                                 $output->disable();
 890
 891                                 return;
 892                         }
 893                 }
 894
 895                 // Actually do the work of the request and build up any output
 896                 $this->performRequest();
 897
 898                 // GUI-ify and stash the page output in MediaWiki::doPreOutputCommit() while
 899                 // ChronologyProtector synchronizes DB positions or replicas across all datacenters.
 900                 $buffer = null;
 901                 $outputWork = function () use ( $output, &$buffer ) {
 902                         if ( $buffer === null ) {
 903                                 $buffer = $output->output( true );
 904                         }
 905
 906                         return $buffer;
 907                 };
 908
 909                 // Now commit any transactions, so that unreported errors after
 910                 // output() don't roll back the whole DB transaction and so that
 911                 // we avoid having both success and error text in the response
 912                 $this->doPreOutputCommit( $outputWork );
 913
 914                 // Now send the actual output
 915                 print $outputWork();
 916         }
 917
 918         /**
 919          * Ends this task peacefully
 920          * @param string $mode Use 'fast' to always skip job running
 921          * @param bool $blocksHttpClient Whether this blocks an HTTP response to a client
 922          */
 923         public function restInPeace( $mode = 'fast', $blocksHttpClient = true ) {
 924                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 925                 // Assure deferred updates are not in the main transaction
 926                 $lbFactory->commitMasterChanges( __METHOD__ );
 927
 928                 // Loosen DB query expectations since the HTTP client is unblocked
 929                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 930                 $trxProfiler->redefineExpectations(
 931                         $this->context->getRequest()->hasSafeMethod()
 932                                 ? $this->config->get( 'TrxProfilerLimits' )['PostSend-GET']
 933                                 : $this->config->get( 'TrxProfilerLimits' )['PostSend-POST'],
 934                         __METHOD__
 935                 );
 936
 937                 // Do any deferred jobs; preferring to run them now if a client will not wait on them
 938                 DeferredUpdates::doUpdates( $blocksHttpClient ? 'enqueue' : 'run' );
 939
 940                 // Now that everything specific to this request is done,
 941                 // try to occasionally run jobs (if enabled) from the queues
 942                 if ( $mode === 'normal' ) {
 943                         $this->triggerJobs();
 944                 }
 945
 946                 // Log profiling data, e.g. in the database or UDP
 947                 wfLogProfilingData();
 948
 949                 // Commit and close up!
 950                 $lbFactory->commitMasterChanges( __METHOD__ );
 951                 $lbFactory->shutdown( $lbFactory::SHUTDOWN_NO_CHRONPROT );
 952
 953                 wfDebug( "Request ended normally\n" );
 954         }
 955
 956         /**
 957          * Send out any buffered statsd data according to sampling rules
 958          *
 959          * @param IBufferingStatsdDataFactory $stats
 960          * @param Config $config
 961          * @throws ConfigException
 962          * @since 1.31
 963          */
 964         public static function emitBufferedStatsdData(
 965                 IBufferingStatsdDataFactory $stats, Config $config
 966         ) {
 967                 if ( $config->get( 'StatsdServer' ) && $stats->hasData() ) {
 968                         try {
 969                                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ), 2 );
 970                                 $statsdHost = $statsdServer[0];
 971                                 $statsdPort = $statsdServer[1] ?? 8125;
 972                                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
 973                                 $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
 974                                 $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
 975                                 $statsdClient->send( $stats->getData() );
 976
 977                                 $stats->clearData(); // empty buffer for the next round
 978                         } catch ( Exception $ex ) {
 979                                 MWExceptionHandler::logException( $ex );
 980                         }
 981                 }
 982         }
 983
 984         /**
 985          * Potentially open a socket and sent an HTTP request back to the server
 986          * to run a specified number of jobs. This registers a callback to cleanup
 987          * the socket once it's done.
 988          */
 989         public function triggerJobs() {
 990                 $jobRunRate = $this->config->get( 'JobRunRate' );
 991                 if ( $this->getTitle()->isSpecial( 'RunJobs' ) ) {
 992                         return; // recursion guard
 993                 } elseif ( $jobRunRate <= 0 || wfReadOnly() ) {
 994                         return;
 995                 }
 996
 997                 if ( $jobRunRate < 1 ) {
 998                         $max = mt_getrandmax();
 999                         if ( mt_rand( 0, $max ) > $max * $jobRunRate ) {
1000                                 return; // the higher the job run rate, the less likely we return here
1001                         }
1002                         $n = 1;
1003                 } else {
1004                         $n = intval( $jobRunRate );
1005                 }
1006
1007                 $logger = LoggerFactory::getInstance( 'runJobs' );
1008
1009                 try {
1010                         if ( $this->config->get( 'RunJobsAsync' ) ) {
1011                                 // Send an HTTP request to the job RPC entry point if possible
1012                                 $invokedWithSuccess = $this->triggerAsyncJobs( $n, $logger );
1013                                 if ( !$invokedWithSuccess ) {
1014                                         // Fall back to blocking on running the job(s)
1015                                         $logger->warning( "Jobs switched to blocking; Special:RunJobs disabled" );
1016                                         $this->triggerSyncJobs( $n, $logger );
1017                                 }
1018                         } else {
1019                                 $this->triggerSyncJobs( $n, $logger );
1020                         }
1021                 } catch ( JobQueueError $e ) {
1022                         // Do not make the site unavailable (T88312)
1023                         MWExceptionHandler::logException( $e );
1024                 }
1025         }
1026
1027         /**
1028          * @param int $n Number of jobs to try to run
1029          * @param LoggerInterface $runJobsLogger
1030          */
1031         private function triggerSyncJobs( $n, LoggerInterface $runJobsLogger ) {
1032                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1033                 $old = $trxProfiler->setSilenced( true );
1034                 try {
1035                         $runner = new JobRunner( $runJobsLogger );
1036                         $runner->run( [ 'maxJobs' => $n ] );
1037                 } finally {
1038                         $trxProfiler->setSilenced( $old );
1039                 }
1040         }
1041
1042         /**
1043          * @param int $n Number of jobs to try to run
1044          * @param LoggerInterface $runJobsLogger
1045          * @return bool Success
1046          */
1047         private function triggerAsyncJobs( $n, LoggerInterface $runJobsLogger ) {
1048                 // Do not send request if there are probably no jobs
1049                 $group = JobQueueGroup::singleton();
1050                 if ( !$group->queuesHaveJobs( JobQueueGroup::TYPE_DEFAULT ) ) {
1051                         return true;
1052                 }
1053
1054                 $query = [ 'title' => 'Special:RunJobs',
1055                         'tasks' => 'jobs', 'maxjobs' => $n, 'sigexpiry' => time() + 5 ];
1056                 $query['signature'] = SpecialRunJobs::getQuerySignature(
1057                         $query, $this->config->get( 'SecretKey' ) );
1058
1059                 $errno = $errstr = null;
1060                 $info = wfParseUrl( $this->config->get( 'CanonicalServer' ) );
1061                 $host = $info ? $info['host'] : null;
1062                 $port = 80;
1063                 if ( isset( $info['scheme'] ) && $info['scheme'] == 'https' ) {
1064                         $host = "tls://" . $host;
1065                         $port = 443;
1066                 }
1067                 if ( isset( $info['port'] ) ) {
1068                         $port = $info['port'];
1069                 }
1070
1071                 Wikimedia\suppressWarnings();
1072                 $sock = $host ? fsockopen(
1073                         $host,
1074                         $port,
1075                         $errno,
1076                         $errstr,
1077                         // If it takes more than 100ms to connect to ourselves there is a problem...
1078                         0.100
1079                 ) : false;
1080                 Wikimedia\restoreWarnings();
1081
1082                 $invokedWithSuccess = true;
1083                 if ( $sock ) {
1084                         $special = MediaWikiServices::getInstance()->getSpecialPageFactory()->
1085                                 getPage( 'RunJobs' );
1086                         $url = $special->getPageTitle()->getCanonicalURL( $query );
1087                         $req = (
1088                                 "POST $url HTTP/1.1\r\n" .
1089                                 "Host: {$info['host']}\r\n" .
1090                                 "Connection: Close\r\n" .
1091                                 "Content-Length: 0\r\n\r\n"
1092                         );
1093
1094                         $runJobsLogger->info( "Running $n job(s) via '$url'" );
1095                         // Send a cron API request to be performed in the background.
1096                         // Give up if this takes too long to send (which should be rare).
1097                         stream_set_timeout( $sock, 2 );
1098                         $bytes = fwrite( $sock, $req );
1099                         if ( $bytes !== strlen( $req ) ) {
1100                                 $invokedWithSuccess = false;
1101                                 $runJobsLogger->error( "Failed to start cron API (socket write error)" );
1102                         } else {
1103                                 // Do not wait for the response (the script should handle client aborts).
1104                                 // Make sure that we don't close before that script reaches ignore_user_abort().
1105                                 $start = microtime( true );
1106                                 $status = fgets( $sock );
1107                                 $sec = microtime( true ) - $start;
1108                                 if ( !preg_match( '#^HTTP/\d\.\d 202 #', $status ) ) {
1109                                         $invokedWithSuccess = false;
1110                                         $runJobsLogger->error( "Failed to start cron API: received '$status' ($sec)" );
1111                                 }
1112                         }
1113                         fclose( $sock );
1114                 } else {
1115                         $invokedWithSuccess = false;
1116                         $runJobsLogger->error( "Failed to start cron API (socket error $errno): $errstr" );
1117                 }
1118
1119                 return $invokedWithSuccess;
1120         }
1121 }