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 ( $title->isSpecialPage() ) {
 350                         list( $name, $subpage ) = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 351                                 resolveAlias( $title->getDBkey() );
 352                         if ( $name ) {
 353                                 $title = SpecialPage::getTitleFor( $name, $subpage );
 354                         }
 355                 }
 356                 // Redirect to canonical url, make it a 301 to allow caching
 357                 $targetUrl = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
 358                 if ( $targetUrl == $request->getFullRequestURL() ) {
 359                         $message = "Redirect loop detected!\n\n" .
 360                                 "This means the wiki got confused about what page was " .
 361                                 "requested; this sometimes happens when moving a wiki " .
 362                                 "to a new server or changing the server configuration.\n\n";
 363
 364                         if ( $this->config->get( 'UsePathInfo' ) ) {
 365                                 $message .= "The wiki is trying to interpret the page " .
 366                                         "title from the URL path portion (PATH_INFO), which " .
 367                                         "sometimes fails depending on the web server. Try " .
 368                                         "setting \"\$wgUsePathInfo = false;\" in your " .
 369                                         "LocalSettings.php, or check that \$wgArticlePath " .
 370                                         "is correct.";
 371                         } else {
 372                                 $message .= "Your web server was detected as possibly not " .
 373                                         "supporting URL path components (PATH_INFO) correctly; " .
 374                                         "check your LocalSettings.php for a customized " .
 375                                         "\$wgArticlePath setting and/or toggle \$wgUsePathInfo " .
 376                                         "to true.";
 377                         }
 378                         throw new HttpError( 500, $message );
 379                 }
 380                 $output->setCdnMaxage( 1200 );
 381                 $output->redirect( $targetUrl, '301' );
 382                 return true;
 383         }
 384
 385         /**
 386          * Initialize the main Article object for "standard" actions (view, etc)
 387          * Create an Article object for the page, following redirects if needed.
 388          *
 389          * @return Article|string An Article, or a string to redirect to another URL
 390          */
 391         private function initializeArticle() {
 392                 $title = $this->context->getTitle();
 393                 if ( $this->context->canUseWikiPage() ) {
 394                         // Try to use request context wiki page, as there
 395                         // is already data from db saved in per process
 396                         // cache there from this->getAction() call.
 397                         $page = $this->context->getWikiPage();
 398                 } else {
 399                         // This case should not happen, but just in case.
 400                         // @TODO: remove this or use an exception
 401                         $page = WikiPage::factory( $title );
 402                         $this->context->setWikiPage( $page );
 403                         wfWarn( "RequestContext::canUseWikiPage() returned false" );
 404                 }
 405
 406                 // Make GUI wrapper for the WikiPage
 407                 $article = Article::newFromWikiPage( $page, $this->context );
 408
 409                 // Skip some unnecessary code if the content model doesn't support redirects
 410                 if ( !ContentHandler::getForTitle( $title )->supportsRedirects() ) {
 411                         return $article;
 412                 }
 413
 414                 $request = $this->context->getRequest();
 415
 416                 // Namespace might change when using redirects
 417                 // Check for redirects ...
 418                 $action = $request->getVal( 'action', 'view' );
 419                 $file = ( $page instanceof WikiFilePage ) ? $page->getFile() : null;
 420                 if ( ( $action == 'view' || $action == 'render' ) // ... for actions that show content
 421                         && !$request->getVal( 'oldid' ) // ... and are not old revisions
 422                         && !$request->getVal( 'diff' ) // ... and not when showing diff
 423                         && $request->getVal( 'redirect' ) != 'no' // ... unless explicitly told not to
 424                         // ... and the article is not a non-redirect image page with associated file
 425                         && !( is_object( $file ) && $file->exists() && !$file->getRedirected() )
 426                 ) {
 427                         // Give extensions a change to ignore/handle redirects as needed
 428                         $ignoreRedirect = $target = false;
 429
 430                         Hooks::run( 'InitializeArticleMaybeRedirect',
 431                                 [ &$title, &$request, &$ignoreRedirect, &$target, &$article ] );
 432                         $page = $article->getPage(); // reflect any hook changes
 433
 434                         // Follow redirects only for... redirects.
 435                         // If $target is set, then a hook wanted to redirect.
 436                         if ( !$ignoreRedirect && ( $target || $page->isRedirect() ) ) {
 437                                 // Is the target already set by an extension?
 438                                 $target = $target ?: $page->followRedirect();
 439                                 if ( is_string( $target ) && !$this->config->get( 'DisableHardRedirects' ) ) {
 440                                         // we'll need to redirect
 441                                         return $target;
 442                                 }
 443                                 if ( is_object( $target ) ) {
 444                                         // Rewrite environment to redirected article
 445                                         $rpage = WikiPage::factory( $target );
 446                                         $rpage->loadPageData();
 447                                         if ( $rpage->exists() || ( is_object( $file ) && !$file->isLocal() ) ) {
 448                                                 $rarticle = Article::newFromWikiPage( $rpage, $this->context );
 449                                                 $rarticle->setRedirectedFrom( $title );
 450
 451                                                 $article = $rarticle;
 452                                                 $this->context->setTitle( $target );
 453                                                 $this->context->setWikiPage( $article->getPage() );
 454                                         }
 455                                 }
 456                         } else {
 457                                 // Article may have been changed by hook
 458                                 $this->context->setTitle( $article->getTitle() );
 459                                 $this->context->setWikiPage( $article->getPage() );
 460                         }
 461                 }
 462
 463                 return $article;
 464         }
 465
 466         /**
 467          * Perform one of the "standard" actions
 468          *
 469          * @param Page $page
 470          * @param Title $requestTitle The original title, before any redirects were applied
 471          */
 472         private function performAction( Page $page, Title $requestTitle ) {
 473                 $request = $this->context->getRequest();
 474                 $output = $this->context->getOutput();
 475                 $title = $this->context->getTitle();
 476                 $user = $this->context->getUser();
 477
 478                 if ( !Hooks::run( 'MediaWikiPerformAction',
 479                                 [ $output, $page, $title, $user, $request, $this ] )
 480                 ) {
 481                         return;
 482                 }
 483
 484                 $act = $this->getAction();
 485                 $action = Action::factory( $act, $page, $this->context );
 486
 487                 if ( $action instanceof Action ) {
 488                         // Narrow DB query expectations for this HTTP request
 489                         $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 490                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 491                         if ( $request->wasPosted() && !$action->doesWrites() ) {
 492                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 493                                 $request->markAsSafeRequest();
 494                         }
 495
 496                         # Let CDN cache things if we can purge them.
 497                         if ( $this->config->get( 'UseCdn' ) &&
 498                                 in_array(
 499                                         // Use PROTO_INTERNAL because that's what getCdnUrls() uses
 500                                         wfExpandUrl( $request->getRequestURL(), PROTO_INTERNAL ),
 501                                         $requestTitle->getCdnUrls()
 502                                 )
 503                         ) {
 504                                 $output->setCdnMaxage( $this->config->get( 'CdnMaxAge' ) );
 505                         }
 506
 507                         $action->show();
 508                         return;
 509                 }
 510
 511                 // If we've not found out which action it is by now, it's unknown
 512                 $output->setStatusCode( 404 );
 513                 $output->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
 514         }
 515
 516         /**
 517          * Run the current MediaWiki instance; index.php just calls this
 518          */
 519         public function run() {
 520                 try {
 521                         $this->setDBProfilingAgent();
 522                         try {
 523                                 $this->main();
 524                         } catch ( ErrorPageError $e ) {
 525                                 // T64091: while exceptions are convenient to bubble up GUI errors,
 526                                 // they are not internal application faults. As with normal requests, this
 527                                 // should commit, print the output, do deferred updates, jobs, and profiling.
 528                                 $this->doPreOutputCommit();
 529                                 $e->report(); // display the GUI error
 530                         }
 531                 } catch ( Exception $e ) {
 532                         $context = $this->context;
 533                         $action = $context->getRequest()->getVal( 'action', 'view' );
 534                         if (
 535                                 $e instanceof DBConnectionError &&
 536                                 $context->hasTitle() &&
 537                                 $context->getTitle()->canExist() &&
 538                                 in_array( $action, [ 'view', 'history' ], true ) &&
 539                                 HTMLFileCache::useFileCache( $this->context, HTMLFileCache::MODE_OUTAGE )
 540                         ) {
 541                                 // Try to use any (even stale) file during outages...
 542                                 $cache = new HTMLFileCache( $context->getTitle(), $action );
 543                                 if ( $cache->isCached() ) {
 544                                         $cache->loadFromFileCache( $context, HTMLFileCache::MODE_OUTAGE );
 545                                         print MWExceptionRenderer::getHTML( $e );
 546                                         exit;
 547                                 }
 548                         }
 549
 550                         MWExceptionHandler::handleException( $e );
 551                 } catch ( Error $e ) {
 552                         // Type errors and such: at least handle it now and clean up the LBFactory state
 553                         MWExceptionHandler::handleException( $e );
 554                 }
 555
 556                 $this->doPostOutputShutdown( 'normal' );
 557         }
 558
 559         private function setDBProfilingAgent() {
 560                 $services = MediaWikiServices::getInstance();
 561                 // Add a comment for easy SHOW PROCESSLIST interpretation
 562                 $name = $this->context->getUser()->getName();
 563                 $services->getDBLoadBalancerFactory()->setAgentName(
 564                         mb_strlen( $name ) > 15 ? mb_substr( $name, 0, 15 ) . '...' : $name
 565                 );
 566         }
 567
 568         /**
 569          * @see MediaWiki::preOutputCommit()
 570          * @param callable|null $postCommitWork [default: null]
 571          * @since 1.26
 572          */
 573         public function doPreOutputCommit( callable $postCommitWork = null ) {
 574                 self::preOutputCommit( $this->context, $postCommitWork );
 575         }
 576
 577         /**
 578          * This function commits all DB and session changes as needed *before* the
 579          * client can receive a response (in case DB commit fails) and thus also before
 580          * the response can trigger a subsequent related request by the client
 581          *
 582          * If there is a significant amount of content to flush, it can be done in $postCommitWork
 583          *
 584          * @param IContextSource $context
 585          * @param callable|null $postCommitWork [default: null]
 586          * @since 1.27
 587          */
 588         public static function preOutputCommit(
 589                 IContextSource $context, callable $postCommitWork = null
 590         ) {
 591                 $config = $context->getConfig();
 592                 $request = $context->getRequest();
 593                 $output = $context->getOutput();
 594                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 595
 596                 // Try to make sure that all RDBMs, session, and other storage updates complete
 597                 ignore_user_abort( true );
 598
 599                 // Commit all RDBMs changes from the main transaction round
 600                 $lbFactory->commitMasterChanges(
 601                         __METHOD__,
 602                         // Abort if any transaction was too big
 603                         [ 'maxWriteDuration' => $config->get( 'MaxUserDBWriteDuration' ) ]
 604                 );
 605                 wfDebug( __METHOD__ . ': primary transaction round committed' );
 606
 607                 // Run updates that need to block the client or affect output (this is the last chance)
 608                 DeferredUpdates::doUpdates( 'run', DeferredUpdates::PRESEND );
 609                 wfDebug( __METHOD__ . ': pre-send deferred updates completed' );
 610                 // Persist the session to avoid race conditions on subsequent requests by the client
 611                 $request->getSession()->save(); // T214471
 612                 wfDebug( __METHOD__ . ': session changes committed' );
 613
 614                 // Figure out whether to wait for DB replication now or to use some method that assures
 615                 // that subsequent requests by the client will use the DB replication positions written
 616                 // during the shutdown() call below; the later requires working around replication lag
 617                 // of the store containing DB replication positions (e.g. dynomite, mcrouter).
 618                 list( $flags, $strategy ) = self::getChronProtStrategy( $lbFactory, $output );
 619                 // Record ChronologyProtector positions for DBs affected in this request at this point
 620                 $cpIndex = null;
 621                 $cpClientId = null;
 622                 $lbFactory->shutdown( $flags, $postCommitWork, $cpIndex, $cpClientId );
 623                 wfDebug( __METHOD__ . ': LBFactory shutdown completed' );
 624
 625                 $allowHeaders = !( $output->isDisabled() || headers_sent() );
 626                 if ( $cpIndex > 0 ) {
 627                         if ( $allowHeaders ) {
 628                                 $now = time();
 629                                 $expires = $now + ChronologyProtector::POSITION_COOKIE_TTL;
 630                                 $options = [ 'prefix' => '' ];
 631                                 $value = $lbFactory::makeCookieValueFromCPIndex( $cpIndex, $now, $cpClientId );
 632                                 $request->response()->setCookie( 'cpPosIndex', $value, $expires, $options );
 633                         }
 634
 635                         if ( $strategy === 'cookie+url' ) {
 636                                 if ( $output->getRedirect() ) { // sanity
 637                                         $safeUrl = $lbFactory->appendShutdownCPIndexAsQuery(
 638                                                 $output->getRedirect(),
 639                                                 $cpIndex
 640                                         );
 641                                         $output->redirect( $safeUrl );
 642                                 } else {
 643                                         $e = new LogicException( "No redirect; cannot append cpPosIndex parameter." );
 644                                         MWExceptionHandler::logException( $e );
 645                                 }
 646                         }
 647                 }
 648
 649                 if ( $allowHeaders ) {
 650                         // Set a cookie to tell all CDN edge nodes to "stick" the user to the DC that
 651                         // handles this POST request (e.g. the "master" data center). Also have the user
 652                         // briefly bypass CDN so ChronologyProtector works for cacheable URLs.
 653                         if ( $request->wasPosted() && $lbFactory->hasOrMadeRecentMasterChanges() ) {
 654                                 $expires = time() + $config->get( 'DataCenterUpdateStickTTL' );
 655                                 $options = [ 'prefix' => '' ];
 656                                 $request->response()->setCookie( 'UseDC', 'master', $expires, $options );
 657                                 $request->response()->setCookie( 'UseCDNCache', 'false', $expires, $options );
 658                         }
 659
 660                         // Avoid letting a few seconds of replica DB lag cause a month of stale data.
 661                         // This logic is also intimately related to the value of $wgCdnReboundPurgeDelay.
 662                         if ( $lbFactory->laggedReplicaUsed() ) {
 663                                 $maxAge = $config->get( 'CdnMaxageLagged' );
 664                                 $output->lowerCdnMaxage( $maxAge );
 665                                 $request->response()->header( "X-Database-Lagged: true" );
 666                                 wfDebugLog( 'replication',
 667                                         "Lagged DB used; CDN cache TTL limited to $maxAge seconds" );
 668                         }
 669
 670                         // Avoid long-term cache pollution due to message cache rebuild timeouts (T133069)
 671                         if ( MessageCache::singleton()->isDisabled() ) {
 672                                 $maxAge = $config->get( 'CdnMaxageSubstitute' );
 673                                 $output->lowerCdnMaxage( $maxAge );
 674                                 $request->response()->header( "X-Response-Substitute: true" );
 675                         }
 676                 }
 677         }
 678
 679         /**
 680          * @param ILBFactory $lbFactory
 681          * @param OutputPage $output
 682          * @return array
 683          */
 684         private static function getChronProtStrategy( ILBFactory $lbFactory, OutputPage $output ) {
 685                 // Should the client return, their request should observe the new ChronologyProtector
 686                 // DB positions. This request might be on a foreign wiki domain, so synchronously update
 687                 // the DB positions in all datacenters to be safe. If this output is not a redirect,
 688                 // then OutputPage::output() will be relatively slow, meaning that running it in
 689                 // $postCommitWork should help mask the latency of those updates.
 690                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_SYNC;
 691                 $strategy = 'cookie+sync';
 692
 693                 $allowHeaders = !( $output->isDisabled() || headers_sent() );
 694                 if ( $output->getRedirect() && $lbFactory->hasOrMadeRecentMasterChanges( INF ) ) {
 695                         // OutputPage::output() will be fast, so $postCommitWork is useless for masking
 696                         // the latency of synchronously updating the DB positions in all datacenters.
 697                         // Try to make use of the time the client spends following redirects instead.
 698                         $domainDistance = self::getUrlDomainDistance( $output->getRedirect() );
 699                         if ( $domainDistance === 'local' && $allowHeaders ) {
 700                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 701                                 $strategy = 'cookie'; // use same-domain cookie and keep the URL uncluttered
 702                         } elseif ( $domainDistance === 'remote' ) {
 703                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 704                                 $strategy = 'cookie+url'; // cross-domain cookie might not work
 705                         }
 706                 }
 707
 708                 return [ $flags, $strategy ];
 709         }
 710
 711         /**
 712          * @param string $url
 713          * @return string Either "local", "remote" if in the farm, "external" otherwise
 714          */
 715         private static function getUrlDomainDistance( $url ) {
 716                 $clusterWiki = WikiMap::getWikiFromUrl( $url );
 717                 if ( WikiMap::isCurrentWikiId( $clusterWiki ) ) {
 718                         return 'local'; // the current wiki
 719                 }
 720                 if ( $clusterWiki !== false ) {
 721                         return 'remote'; // another wiki in this cluster/farm
 722                 }
 723
 724                 return 'external';
 725         }
 726
 727         /**
 728          * This function does work that can be done *after* the
 729          * user gets the HTTP response so they don't block on it
 730          *
 731          * This manages deferred updates, job insertion,
 732          * final commit, and the logging of profiling data
 733          *
 734          * @param string $mode Use 'fast' to always skip job running
 735          * @since 1.26
 736          */
 737         public function doPostOutputShutdown( $mode = 'normal' ) {
 738                 // Record backend request timing
 739                 $timing = $this->context->getTiming();
 740                 $timing->mark( 'requestShutdown' );
 741
 742                 // Perform the last synchronous operations...
 743                 try {
 744                         // Show visible profiling data if enabled (which cannot be post-send)
 745                         Profiler::instance()->logDataPageOutputOnly();
 746                 } catch ( Exception $e ) {
 747                         // An error may already have been shown in run(), so just log it to be safe
 748                         MWExceptionHandler::logException( $e );
 749                 }
 750
 751                 // Disable WebResponse setters for post-send processing (T191537).
 752                 WebResponse::disableForPostSend();
 753
 754                 $blocksHttpClient = true;
 755                 // Defer everything else if possible...
 756                 $callback = function () use ( $mode, &$blocksHttpClient ) {
 757                         try {
 758                                 $this->restInPeace( $mode, $blocksHttpClient );
 759                         } catch ( Exception $e ) {
 760                                 // If this is post-send, then displaying errors can cause broken HTML
 761                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 762                         }
 763                 };
 764
 765                 if ( function_exists( 'register_postsend_function' ) ) {
 766                         // https://github.com/facebook/hhvm/issues/1230
 767                         register_postsend_function( $callback );
 768                         /** @noinspection PhpUnusedLocalVariableInspection */
 769                         $blocksHttpClient = false;
 770                 } else {
 771                         if ( function_exists( 'fastcgi_finish_request' ) ) {
 772                                 fastcgi_finish_request();
 773                                 /** @noinspection PhpUnusedLocalVariableInspection */
 774                                 $blocksHttpClient = false;
 775                         } else {
 776                                 // Either all DB and deferred updates should happen or none.
 777                                 // The latter should not be cancelled due to client disconnect.
 778                                 ignore_user_abort( true );
 779                         }
 780
 781                         $callback();
 782                 }
 783         }
 784
 785         private function main() {
 786                 global $wgTitle;
 787
 788                 $output = $this->context->getOutput();
 789                 $request = $this->context->getRequest();
 790
 791                 // Send Ajax requests to the Ajax dispatcher.
 792                 if ( $request->getVal( 'action' ) === 'ajax' ) {
 793                         // Set a dummy title, because $wgTitle == null might break things
 794                         $title = Title::makeTitle( NS_SPECIAL, 'Badtitle/performing an AJAX call in '
 795                                 . __METHOD__
 796                         );
 797                         $this->context->setTitle( $title );
 798                         $wgTitle = $title;
 799
 800                         $dispatcher = new AjaxDispatcher( $this->config );
 801                         $dispatcher->performAction( $this->context->getUser() );
 802
 803                         return;
 804                 }
 805
 806                 // Get title from request parameters,
 807                 // is set on the fly by parseTitle the first time.
 808                 $title = $this->getTitle();
 809                 $action = $this->getAction();
 810                 $wgTitle = $title;
 811
 812                 // Set DB query expectations for this HTTP request
 813                 $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 814                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 815                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
 816                 if ( $request->hasSafeMethod() ) {
 817                         $trxProfiler->setExpectations( $trxLimits['GET'], __METHOD__ );
 818                 } else {
 819                         $trxProfiler->setExpectations( $trxLimits['POST'], __METHOD__ );
 820                 }
 821
 822                 // If the user has forceHTTPS set to true, or if the user
 823                 // is in a group requiring HTTPS, or if they have the HTTPS
 824                 // preference set, redirect them to HTTPS.
 825                 // Note: Do this after $wgTitle is setup, otherwise the hooks run from
 826                 // isLoggedIn() will do all sorts of weird stuff.
 827                 if (
 828                         $request->getProtocol() == 'http' &&
 829                         // switch to HTTPS only when supported by the server
 830                         preg_match( '#^https://#', wfExpandUrl( $request->getRequestURL(), PROTO_HTTPS ) ) &&
 831                         (
 832                                 $request->getSession()->shouldForceHTTPS() ||
 833                                 // Check the cookie manually, for paranoia
 834                                 $request->getCookie( 'forceHTTPS', '' ) ||
 835                                 // check for prefixed version that was used for a time in older MW versions
 836                                 $request->getCookie( 'forceHTTPS' ) ||
 837                                 // Avoid checking the user and groups unless it's enabled.
 838                                 (
 839                                         $this->context->getUser()->isLoggedIn()
 840                                         && $this->context->getUser()->requiresHTTPS()
 841                                 )
 842                         )
 843                 ) {
 844                         $oldUrl = $request->getFullRequestURL();
 845                         $redirUrl = preg_replace( '#^http://#', 'https://', $oldUrl );
 846
 847                         // ATTENTION: This hook is likely to be removed soon due to overall design of the system.
 848                         if ( Hooks::run( 'BeforeHttpsRedirect', [ $this->context, &$redirUrl ] ) ) {
 849                                 if ( $request->wasPosted() ) {
 850                                         // This is weird and we'd hope it almost never happens. This
 851                                         // means that a POST came in via HTTP and policy requires us
 852                                         // redirecting to HTTPS. It's likely such a request is going
 853                                         // to fail due to post data being lost, but let's try anyway
 854                                         // and just log the instance.
 855
 856                                         // @todo FIXME: See if we could issue a 307 or 308 here, need
 857                                         // to see how clients (automated & browser) behave when we do
 858                                         wfDebugLog( 'RedirectedPosts', "Redirected from HTTP to HTTPS: $oldUrl" );
 859                                 }
 860                                 // Setup dummy Title, otherwise OutputPage::redirect will fail
 861                                 $title = Title::newFromText( 'REDIR', NS_MAIN );
 862                                 $this->context->setTitle( $title );
 863                                 // Since we only do this redir to change proto, always send a vary header
 864                                 $output->addVaryHeader( 'X-Forwarded-Proto' );
 865                                 $output->redirect( $redirUrl );
 866                                 $output->output();
 867
 868                                 return;
 869                         }
 870                 }
 871
 872                 if ( $title->canExist() && HTMLFileCache::useFileCache( $this->context ) ) {
 873                         // Try low-level file cache hit
 874                         $cache = new HTMLFileCache( $title, $action );
 875                         if ( $cache->isCacheGood( /* Assume up to date */ ) ) {
 876                                 // Check incoming headers to see if client has this cached
 877                                 $timestamp = $cache->cacheTimestamp();
 878                                 if ( !$output->checkLastModified( $timestamp ) ) {
 879                                         $cache->loadFromFileCache( $this->context );
 880                                 }
 881                                 // Do any stats increment/watchlist stuff, assuming user is viewing the
 882                                 // latest revision (which should always be the case for file cache)
 883                                 $this->context->getWikiPage()->doViewUpdates( $this->context->getUser() );
 884                                 // Tell OutputPage that output is taken care of
 885                                 $output->disable();
 886
 887                                 return;
 888                         }
 889                 }
 890
 891                 // Actually do the work of the request and build up any output
 892                 $this->performRequest();
 893
 894                 // GUI-ify and stash the page output in MediaWiki::doPreOutputCommit() while
 895                 // ChronologyProtector synchronizes DB positions or replicas across all datacenters.
 896                 $buffer = null;
 897                 $outputWork = function () use ( $output, &$buffer ) {
 898                         if ( $buffer === null ) {
 899                                 $buffer = $output->output( true );
 900                         }
 901
 902                         return $buffer;
 903                 };
 904
 905                 // Now commit any transactions, so that unreported errors after
 906                 // output() don't roll back the whole DB transaction and so that
 907                 // we avoid having both success and error text in the response
 908                 $this->doPreOutputCommit( $outputWork );
 909
 910                 // Now send the actual output
 911                 print $outputWork();
 912         }
 913
 914         /**
 915          * Ends this task peacefully
 916          * @param string $mode Use 'fast' to always skip job running
 917          * @param bool $blocksHttpClient Whether this blocks an HTTP response to a client
 918          */
 919         public function restInPeace( $mode = 'fast', $blocksHttpClient = true ) {
 920                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 921                 // Assure deferred updates are not in the main transaction
 922                 $lbFactory->commitMasterChanges( __METHOD__ );
 923
 924                 // Loosen DB query expectations since the HTTP client is unblocked
 925                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 926                 $trxProfiler->redefineExpectations(
 927                         $this->context->getRequest()->hasSafeMethod()
 928                                 ? $this->config->get( 'TrxProfilerLimits' )['PostSend-GET']
 929                                 : $this->config->get( 'TrxProfilerLimits' )['PostSend-POST'],
 930                         __METHOD__
 931                 );
 932
 933                 // Do any deferred jobs; preferring to run them now if a client will not wait on them
 934                 DeferredUpdates::doUpdates( $blocksHttpClient ? 'enqueue' : 'run' );
 935
 936                 // Now that everything specific to this request is done,
 937                 // try to occasionally run jobs (if enabled) from the queues
 938                 if ( $mode === 'normal' ) {
 939                         $this->triggerJobs();
 940                 }
 941
 942                 // Log profiling data, e.g. in the database or UDP
 943                 wfLogProfilingData();
 944
 945                 // Commit and close up!
 946                 $lbFactory->commitMasterChanges( __METHOD__ );
 947                 $lbFactory->shutdown( $lbFactory::SHUTDOWN_NO_CHRONPROT );
 948
 949                 wfDebug( "Request ended normally\n" );
 950         }
 951
 952         /**
 953          * Send out any buffered statsd data according to sampling rules
 954          *
 955          * @param IBufferingStatsdDataFactory $stats
 956          * @param Config $config
 957          * @throws ConfigException
 958          * @since 1.31
 959          */
 960         public static function emitBufferedStatsdData(
 961                 IBufferingStatsdDataFactory $stats, Config $config
 962         ) {
 963                 if ( $config->get( 'StatsdServer' ) && $stats->hasData() ) {
 964                         try {
 965                                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ), 2 );
 966                                 $statsdHost = $statsdServer[0];
 967                                 $statsdPort = $statsdServer[1] ?? 8125;
 968                                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
 969                                 $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
 970                                 $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
 971                                 $statsdClient->send( $stats->getData() );
 972
 973                                 $stats->clearData(); // empty buffer for the next round
 974                         } catch ( Exception $ex ) {
 975                                 MWExceptionHandler::logException( $ex );
 976                         }
 977                 }
 978         }
 979
 980         /**
 981          * Potentially open a socket and sent an HTTP request back to the server
 982          * to run a specified number of jobs. This registers a callback to cleanup
 983          * the socket once it's done.
 984          */
 985         public function triggerJobs() {
 986                 $jobRunRate = $this->config->get( 'JobRunRate' );
 987                 if ( $this->getTitle()->isSpecial( 'RunJobs' ) ) {
 988                         return; // recursion guard
 989                 } elseif ( $jobRunRate <= 0 || wfReadOnly() ) {
 990                         return;
 991                 }
 992
 993                 if ( $jobRunRate < 1 ) {
 994                         $max = mt_getrandmax();
 995                         if ( mt_rand( 0, $max ) > $max * $jobRunRate ) {
 996                                 return; // the higher the job run rate, the less likely we return here
 997                         }
 998                         $n = 1;
 999                 } else {
1000                         $n = intval( $jobRunRate );
1001                 }
1002
1003                 $logger = LoggerFactory::getInstance( 'runJobs' );
1004
1005                 try {
1006                         if ( $this->config->get( 'RunJobsAsync' ) ) {
1007                                 // Send an HTTP request to the job RPC entry point if possible
1008                                 $invokedWithSuccess = $this->triggerAsyncJobs( $n, $logger );
1009                                 if ( !$invokedWithSuccess ) {
1010                                         // Fall back to blocking on running the job(s)
1011                                         $logger->warning( "Jobs switched to blocking; Special:RunJobs disabled" );
1012                                         $this->triggerSyncJobs( $n, $logger );
1013                                 }
1014                         } else {
1015                                 $this->triggerSyncJobs( $n, $logger );
1016                         }
1017                 } catch ( JobQueueError $e ) {
1018                         // Do not make the site unavailable (T88312)
1019                         MWExceptionHandler::logException( $e );
1020                 }
1021         }
1022
1023         /**
1024          * @param int $n Number of jobs to try to run
1025          * @param LoggerInterface $runJobsLogger
1026          */
1027         private function triggerSyncJobs( $n, LoggerInterface $runJobsLogger ) {
1028                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1029                 $old = $trxProfiler->setSilenced( true );
1030                 try {
1031                         $runner = new JobRunner( $runJobsLogger );
1032                         $runner->run( [ 'maxJobs' => $n ] );
1033                 } finally {
1034                         $trxProfiler->setSilenced( $old );
1035                 }
1036         }
1037
1038         /**
1039          * @param int $n Number of jobs to try to run
1040          * @param LoggerInterface $runJobsLogger
1041          * @return bool Success
1042          */
1043         private function triggerAsyncJobs( $n, LoggerInterface $runJobsLogger ) {
1044                 // Do not send request if there are probably no jobs
1045                 $group = JobQueueGroup::singleton();
1046                 if ( !$group->queuesHaveJobs( JobQueueGroup::TYPE_DEFAULT ) ) {
1047                         return true;
1048                 }
1049
1050                 $query = [ 'title' => 'Special:RunJobs',
1051                         'tasks' => 'jobs', 'maxjobs' => $n, 'sigexpiry' => time() + 5 ];
1052                 $query['signature'] = SpecialRunJobs::getQuerySignature(
1053                         $query, $this->config->get( 'SecretKey' ) );
1054
1055                 $errno = $errstr = null;
1056                 $info = wfParseUrl( $this->config->get( 'CanonicalServer' ) );
1057                 $host = $info ? $info['host'] : null;
1058                 $port = 80;
1059                 if ( isset( $info['scheme'] ) && $info['scheme'] == 'https' ) {
1060                         $host = "tls://" . $host;
1061                         $port = 443;
1062                 }
1063                 if ( isset( $info['port'] ) ) {
1064                         $port = $info['port'];
1065                 }
1066
1067                 Wikimedia\suppressWarnings();
1068                 $sock = $host ? fsockopen(
1069                         $host,
1070                         $port,
1071                         $errno,
1072                         $errstr,
1073                         // If it takes more than 100ms to connect to ourselves there is a problem...
1074                         0.100
1075                 ) : false;
1076                 Wikimedia\restoreWarnings();
1077
1078                 $invokedWithSuccess = true;
1079                 if ( $sock ) {
1080                         $special = MediaWikiServices::getInstance()->getSpecialPageFactory()->
1081                                 getPage( 'RunJobs' );
1082                         $url = $special->getPageTitle()->getCanonicalURL( $query );
1083                         $req = (
1084                                 "POST $url HTTP/1.1\r\n" .
1085                                 "Host: {$info['host']}\r\n" .
1086                                 "Connection: Close\r\n" .
1087                                 "Content-Length: 0\r\n\r\n"
1088                         );
1089
1090                         $runJobsLogger->info( "Running $n job(s) via '$url'" );
1091                         // Send a cron API request to be performed in the background.
1092                         // Give up if this takes too long to send (which should be rare).
1093                         stream_set_timeout( $sock, 2 );
1094                         $bytes = fwrite( $sock, $req );
1095                         if ( $bytes !== strlen( $req ) ) {
1096                                 $invokedWithSuccess = false;
1097                                 $runJobsLogger->error( "Failed to start cron API (socket write error)" );
1098                         } else {
1099                                 // Do not wait for the response (the script should handle client aborts).
1100                                 // Make sure that we don't close before that script reaches ignore_user_abort().
1101                                 $start = microtime( true );
1102                                 $status = fgets( $sock );
1103                                 $sec = microtime( true ) - $start;
1104                                 if ( !preg_match( '#^HTTP/\d\.\d 202 #', $status ) ) {
1105                                         $invokedWithSuccess = false;
1106                                         $runJobsLogger->error( "Failed to start cron API: received '$status' ($sec)" );
1107                                 }
1108                         }
1109                         fclose( $sock );
1110                 } else {
1111                         $invokedWithSuccess = false;
1112                         $runJobsLogger->error( "Failed to start cron API (socket error $errno): $errstr" );
1113                 }
1114
1115                 return $invokedWithSuccess;
1116         }
1117 }