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\ChronologyProtector;
  27 use Wikimedia\Rdbms\LBFactory;
  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                                                         $query = $specialPage->getRedirectQuery() ?: [];
 266                                                         $request = new DerivativeRequest( $this->context->getRequest(), $query );
 267                                                         $request->setRequestURL( $this->context->getRequest()->getRequestURL() );
 268                                                         $this->context->setRequest( $request );
 269                                                         // Do not varnish cache these. May vary even for anons
 270                                                         $this->context->getOutput()->lowerCdnMaxage( 0 );
 271                                                         $this->context->setTitle( $target );
 272                                                         $wgTitle = $target;
 273                                                         // Reset action type cache. (Special pages have only view)
 274                                                         $this->action = null;
 275                                                         $title = $target;
 276                                                         $output->addJsConfigVars( [
 277                                                                 'wgInternalRedirectTargetUrl' => $target->getFullURL( $query ),
 278                                                         ] );
 279                                                         $output->addModules( 'mediawiki.action.view.redirect' );
 280                                                 }
 281                                         }
 282                                 }
 283                         }
 284
 285                         // Special pages ($title may have changed since if statement above)
 286                         if ( $title->isSpecialPage() ) {
 287                                 // Actions that need to be made when we have a special pages
 288                                 $spFactory->executePath( $title, $this->context );
 289                         } else {
 290                                 // ...otherwise treat it as an article view. The article
 291                                 // may still be a wikipage redirect to another article or URL.
 292                                 $article = $this->initializeArticle();
 293                                 if ( is_object( $article ) ) {
 294                                         $this->performAction( $article, $requestTitle );
 295                                 } elseif ( is_string( $article ) ) {
 296                                         $output->redirect( $article );
 297                                 } else {
 298                                         throw new MWException( "Shouldn't happen: MediaWiki::initializeArticle()"
 299                                                 . " returned neither an object nor a URL" );
 300                                 }
 301                         }
 302                 }
 303         }
 304
 305         /**
 306          * Handle redirects for uncanonical title requests.
 307          *
 308          * Handles:
 309          * - Redirect loops.
 310          * - No title in URL.
 311          * - $wgUsePathInfo URLs.
 312          * - URLs with a variant.
 313          * - Other non-standard URLs (as long as they have no extra query parameters).
 314          *
 315          * Behaviour:
 316          * - Normalise title values:
 317          *   /wiki/Foo%20Bar -> /wiki/Foo_Bar
 318          * - Normalise empty title:
 319          *   /wiki/ -> /wiki/Main
 320          *   /w/index.php?title= -> /wiki/Main
 321          * - Don't redirect anything with query parameters other than 'title' or 'action=view'.
 322          *
 323          * @param Title $title
 324          * @return bool True if a redirect was set.
 325          * @throws HttpError
 326          */
 327         private function tryNormaliseRedirect( Title $title ) {
 328                 $request = $this->context->getRequest();
 329                 $output = $this->context->getOutput();
 330
 331                 if ( $request->getVal( 'action', 'view' ) != 'view'
 332                         || $request->wasPosted()
 333                         || ( $request->getVal( 'title' ) !== null
 334                                 && $title->getPrefixedDBkey() == $request->getVal( 'title' ) )
 335                         || count( $request->getValueNames( [ 'action', 'title' ] ) )
 336                         || !Hooks::run( 'TestCanonicalRedirect', [ $request, $title, $output ] )
 337                 ) {
 338                         return false;
 339                 }
 340
 341                 if ( $title->isSpecialPage() ) {
 342                         list( $name, $subpage ) = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 343                                 resolveAlias( $title->getDBkey() );
 344                         if ( $name ) {
 345                                 $title = SpecialPage::getTitleFor( $name, $subpage );
 346                         }
 347                 }
 348                 // Redirect to canonical url, make it a 301 to allow caching
 349                 $targetUrl = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
 350                 if ( $targetUrl == $request->getFullRequestURL() ) {
 351                         $message = "Redirect loop detected!\n\n" .
 352                                 "This means the wiki got confused about what page was " .
 353                                 "requested; this sometimes happens when moving a wiki " .
 354                                 "to a new server or changing the server configuration.\n\n";
 355
 356                         if ( $this->config->get( 'UsePathInfo' ) ) {
 357                                 $message .= "The wiki is trying to interpret the page " .
 358                                         "title from the URL path portion (PATH_INFO), which " .
 359                                         "sometimes fails depending on the web server. Try " .
 360                                         "setting \"\$wgUsePathInfo = false;\" in your " .
 361                                         "LocalSettings.php, or check that \$wgArticlePath " .
 362                                         "is correct.";
 363                         } else {
 364                                 $message .= "Your web server was detected as possibly not " .
 365                                         "supporting URL path components (PATH_INFO) correctly; " .
 366                                         "check your LocalSettings.php for a customized " .
 367                                         "\$wgArticlePath setting and/or toggle \$wgUsePathInfo " .
 368                                         "to true.";
 369                         }
 370                         throw new HttpError( 500, $message );
 371                 }
 372                 // Protect against redirects to NS_MEDIA namespace
 373                 // when the user probably wants NS_FILE
 374                 if ( $title->inNamespace( NS_MEDIA ) ) {
 375                         $title->mNamespace = NS_FILE;
 376                 }
 377                 $output->setCdnMaxage( 1200 );
 378                 $output->redirect( $targetUrl, '301' );
 379                 return true;
 380         }
 381
 382         /**
 383          * Initialize the main Article object for "standard" actions (view, etc)
 384          * Create an Article object for the page, following redirects if needed.
 385          *
 386          * @return Article|string An Article, or a string to redirect to another URL
 387          */
 388         private function initializeArticle() {
 389                 $title = $this->context->getTitle();
 390                 if ( $this->context->canUseWikiPage() ) {
 391                         // Try to use request context wiki page, as there
 392                         // is already data from db saved in per process
 393                         // cache there from this->getAction() call.
 394                         $page = $this->context->getWikiPage();
 395                 } else {
 396                         // This case should not happen, but just in case.
 397                         // @TODO: remove this or use an exception
 398                         $page = WikiPage::factory( $title );
 399                         $this->context->setWikiPage( $page );
 400                         wfWarn( "RequestContext::canUseWikiPage() returned false" );
 401                 }
 402
 403                 // Make GUI wrapper for the WikiPage
 404                 $article = Article::newFromWikiPage( $page, $this->context );
 405
 406                 // Skip some unnecessary code if the content model doesn't support redirects
 407                 if ( !ContentHandler::getForTitle( $title )->supportsRedirects() ) {
 408                         return $article;
 409                 }
 410
 411                 $request = $this->context->getRequest();
 412
 413                 // Namespace might change when using redirects
 414                 // Check for redirects ...
 415                 $action = $request->getVal( 'action', 'view' );
 416                 $file = ( $page instanceof WikiFilePage ) ? $page->getFile() : null;
 417                 if ( ( $action == 'view' || $action == 'render' ) // ... for actions that show content
 418                         && !$request->getVal( 'oldid' ) // ... and are not old revisions
 419                         && !$request->getVal( 'diff' ) // ... and not when showing diff
 420                         && $request->getVal( 'redirect' ) != 'no' // ... unless explicitly told not to
 421                         // ... and the article is not a non-redirect image page with associated file
 422                         && !( is_object( $file ) && $file->exists() && !$file->getRedirected() )
 423                 ) {
 424                         // Give extensions a change to ignore/handle redirects as needed
 425                         $ignoreRedirect = $target = false;
 426
 427                         Hooks::run( 'InitializeArticleMaybeRedirect',
 428                                 [ &$title, &$request, &$ignoreRedirect, &$target, &$article ] );
 429                         $page = $article->getPage(); // reflect any hook changes
 430
 431                         // Follow redirects only for... redirects.
 432                         // If $target is set, then a hook wanted to redirect.
 433                         if ( !$ignoreRedirect && ( $target || $page->isRedirect() ) ) {
 434                                 // Is the target already set by an extension?
 435                                 $target = $target ?: $page->followRedirect();
 436                                 if ( is_string( $target ) ) {
 437                                         if ( !$this->config->get( 'DisableHardRedirects' ) ) {
 438                                                 // we'll need to redirect
 439                                                 return $target;
 440                                         }
 441                                 }
 442                                 if ( is_object( $target ) ) {
 443                                         // Rewrite environment to redirected article
 444                                         $rpage = WikiPage::factory( $target );
 445                                         $rpage->loadPageData();
 446                                         if ( $rpage->exists() || ( is_object( $file ) && !$file->isLocal() ) ) {
 447                                                 $rarticle = Article::newFromWikiPage( $rpage, $this->context );
 448                                                 $rarticle->setRedirectedFrom( $title );
 449
 450                                                 $article = $rarticle;
 451                                                 $this->context->setTitle( $target );
 452                                                 $this->context->setWikiPage( $article->getPage() );
 453                                         }
 454                                 }
 455                         } else {
 456                                 // Article may have been changed by hook
 457                                 $this->context->setTitle( $article->getTitle() );
 458                                 $this->context->setWikiPage( $article->getPage() );
 459                         }
 460                 }
 461
 462                 return $article;
 463         }
 464
 465         /**
 466          * Perform one of the "standard" actions
 467          *
 468          * @param Page $page
 469          * @param Title $requestTitle The original title, before any redirects were applied
 470          */
 471         private function performAction( Page $page, Title $requestTitle ) {
 472                 $request = $this->context->getRequest();
 473                 $output = $this->context->getOutput();
 474                 $title = $this->context->getTitle();
 475                 $user = $this->context->getUser();
 476
 477                 if ( !Hooks::run( 'MediaWikiPerformAction',
 478                                 [ $output, $page, $title, $user, $request, $this ] )
 479                 ) {
 480                         return;
 481                 }
 482
 483                 $act = $this->getAction();
 484                 $action = Action::factory( $act, $page, $this->context );
 485
 486                 if ( $action instanceof Action ) {
 487                         // Narrow DB query expectations for this HTTP request
 488                         $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 489                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 490                         if ( $request->wasPosted() && !$action->doesWrites() ) {
 491                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 492                                 $request->markAsSafeRequest();
 493                         }
 494
 495                         # Let CDN cache things if we can purge them.
 496                         if ( $this->config->get( 'UseSquid' ) &&
 497                                 in_array(
 498                                         // Use PROTO_INTERNAL because that's what getCdnUrls() uses
 499                                         wfExpandUrl( $request->getRequestURL(), PROTO_INTERNAL ),
 500                                         $requestTitle->getCdnUrls()
 501                                 )
 502                         ) {
 503                                 $output->setCdnMaxage( $this->config->get( 'SquidMaxage' ) );
 504                         }
 505
 506                         $action->show();
 507                         return;
 508                 }
 509                 // NOTE: deprecated hook. Add to $wgActions instead
 510                 if ( Hooks::run(
 511                         'UnknownAction',
 512                         [
 513                                 $request->getVal( 'action', 'view' ),
 514                                 $page
 515                         ],
 516                         '1.19'
 517                 ) ) {
 518                         $output->setStatusCode( 404 );
 519                         $output->showErrorPage( 'nosuchaction', 'nosuchactiontext' );
 520                 }
 521         }
 522
 523         /**
 524          * Run the current MediaWiki instance; index.php just calls this
 525          */
 526         public function run() {
 527                 try {
 528                         $this->setDBProfilingAgent();
 529                         try {
 530                                 $this->main();
 531                         } catch ( ErrorPageError $e ) {
 532                                 // T64091: while exceptions are convenient to bubble up GUI errors,
 533                                 // they are not internal application faults. As with normal requests, this
 534                                 // should commit, print the output, do deferred updates, jobs, and profiling.
 535                                 $this->doPreOutputCommit();
 536                                 $e->report(); // display the GUI error
 537                         }
 538                 } catch ( Exception $e ) {
 539                         $context = $this->context;
 540                         $action = $context->getRequest()->getVal( 'action', 'view' );
 541                         if (
 542                                 $e instanceof DBConnectionError &&
 543                                 $context->hasTitle() &&
 544                                 $context->getTitle()->canExist() &&
 545                                 in_array( $action, [ 'view', 'history' ], true ) &&
 546                                 HTMLFileCache::useFileCache( $this->context, HTMLFileCache::MODE_OUTAGE )
 547                         ) {
 548                                 // Try to use any (even stale) file during outages...
 549                                 $cache = new HTMLFileCache( $context->getTitle(), $action );
 550                                 if ( $cache->isCached() ) {
 551                                         $cache->loadFromFileCache( $context, HTMLFileCache::MODE_OUTAGE );
 552                                         print MWExceptionRenderer::getHTML( $e );
 553                                         exit;
 554                                 }
 555                         }
 556
 557                         MWExceptionHandler::handleException( $e );
 558                 } catch ( Error $e ) {
 559                         // Type errors and such: at least handle it now and clean up the LBFactory state
 560                         MWExceptionHandler::handleException( $e );
 561                 }
 562
 563                 $this->doPostOutputShutdown( 'normal' );
 564         }
 565
 566         private function setDBProfilingAgent() {
 567                 $services = MediaWikiServices::getInstance();
 568                 // Add a comment for easy SHOW PROCESSLIST interpretation
 569                 $name = $this->context->getUser()->getName();
 570                 $services->getDBLoadBalancerFactory()->setAgentName(
 571                         mb_strlen( $name ) > 15 ? mb_substr( $name, 0, 15 ) . '...' : $name
 572                 );
 573         }
 574
 575         /**
 576          * @see MediaWiki::preOutputCommit()
 577          * @param callable|null $postCommitWork [default: null]
 578          * @since 1.26
 579          */
 580         public function doPreOutputCommit( callable $postCommitWork = null ) {
 581                 self::preOutputCommit( $this->context, $postCommitWork );
 582         }
 583
 584         /**
 585          * This function commits all DB changes as needed before
 586          * the user can receive a response (in case commit fails)
 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                 // Either all DBs should commit or none
 596                 ignore_user_abort( true );
 597
 598                 $config = $context->getConfig();
 599                 $request = $context->getRequest();
 600                 $output = $context->getOutput();
 601                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 602
 603                 // Commit all changes
 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 user or affect output (this is the last chance)
 612                 DeferredUpdates::doUpdates( 'enqueue', DeferredUpdates::PRESEND );
 613                 wfDebug( __METHOD__ . ': pre-send deferred updates completed' );
 614
 615                 // Should the client return, their request should observe the new ChronologyProtector
 616                 // DB positions. This request might be on a foreign wiki domain, so synchronously update
 617                 // the DB positions in all datacenters to be safe. If this output is not a redirect,
 618                 // then OutputPage::output() will be relatively slow, meaning that running it in
 619                 // $postCommitWork should help mask the latency of those updates.
 620                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_SYNC;
 621                 $strategy = 'cookie+sync';
 622
 623                 $allowHeaders = !( $output->isDisabled() || headers_sent() );
 624                 if ( $output->getRedirect() && $lbFactory->hasOrMadeRecentMasterChanges( INF ) ) {
 625                         // OutputPage::output() will be fast, so $postCommitWork is useless for masking
 626                         // the latency of synchronously updating the DB positions in all datacenters.
 627                         // Try to make use of the time the client spends following redirects instead.
 628                         $domainDistance = self::getUrlDomainDistance( $output->getRedirect() );
 629                         if ( $domainDistance === 'local' && $allowHeaders ) {
 630                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 631                                 $strategy = 'cookie'; // use same-domain cookie and keep the URL uncluttered
 632                         } elseif ( $domainDistance === 'remote' ) {
 633                                 $flags = $lbFactory::SHUTDOWN_CHRONPROT_ASYNC;
 634                                 $strategy = 'cookie+url'; // cross-domain cookie might not work
 635                         }
 636                 }
 637
 638                 // Record ChronologyProtector positions for DBs affected in this request at this point
 639                 $cpIndex = null;
 640                 $cpClientId = null;
 641                 $lbFactory->shutdown( $flags, $postCommitWork, $cpIndex, $cpClientId );
 642                 wfDebug( __METHOD__ . ': LBFactory shutdown completed' );
 643
 644                 if ( $cpIndex > 0 ) {
 645                         if ( $allowHeaders ) {
 646                                 $now = time();
 647                                 $expires = $now + ChronologyProtector::POSITION_COOKIE_TTL;
 648                                 $options = [ 'prefix' => '' ];
 649                                 $value = LBFactory::makeCookieValueFromCPIndex( $cpIndex, $now, $cpClientId );
 650                                 $request->response()->setCookie( 'cpPosIndex', $value, $expires, $options );
 651                         }
 652
 653                         if ( $strategy === 'cookie+url' ) {
 654                                 if ( $output->getRedirect() ) { // sanity
 655                                         $safeUrl = $lbFactory->appendShutdownCPIndexAsQuery(
 656                                                 $output->getRedirect(),
 657                                                 $cpIndex
 658                                         );
 659                                         $output->redirect( $safeUrl );
 660                                 } else {
 661                                         $e = new LogicException( "No redirect; cannot append cpPosIndex parameter." );
 662                                         MWExceptionHandler::logException( $e );
 663                                 }
 664                         }
 665                 }
 666
 667                 // Set a cookie to tell all CDN edge nodes to "stick" the user to the DC that handles this
 668                 // POST request (e.g. the "master" data center). Also have the user briefly bypass CDN so
 669                 // ChronologyProtector works for cacheable URLs.
 670                 if ( $request->wasPosted() && $lbFactory->hasOrMadeRecentMasterChanges() ) {
 671                         $expires = time() + $config->get( 'DataCenterUpdateStickTTL' );
 672                         $options = [ 'prefix' => '' ];
 673                         $request->response()->setCookie( 'UseDC', 'master', $expires, $options );
 674                         $request->response()->setCookie( 'UseCDNCache', 'false', $expires, $options );
 675                 }
 676
 677                 // Avoid letting a few seconds of replica DB lag cause a month of stale data. This logic is
 678                 // also intimately related to the value of $wgCdnReboundPurgeDelay.
 679                 if ( $lbFactory->laggedReplicaUsed() ) {
 680                         $maxAge = $config->get( 'CdnMaxageLagged' );
 681                         $output->lowerCdnMaxage( $maxAge );
 682                         $request->response()->header( "X-Database-Lagged: true" );
 683                         wfDebugLog( 'replication', "Lagged DB used; CDN cache TTL limited to $maxAge seconds" );
 684                 }
 685
 686                 // Avoid long-term cache pollution due to message cache rebuild timeouts (T133069)
 687                 if ( MessageCache::singleton()->isDisabled() ) {
 688                         $maxAge = $config->get( 'CdnMaxageSubstitute' );
 689                         $output->lowerCdnMaxage( $maxAge );
 690                         $request->response()->header( "X-Response-Substitute: true" );
 691                 }
 692         }
 693
 694         /**
 695          * @param string $url
 696          * @return string Either "local", "remote" if in the farm, "external" otherwise
 697          */
 698         private static function getUrlDomainDistance( $url ) {
 699                 $clusterWiki = WikiMap::getWikiFromUrl( $url );
 700                 if ( $clusterWiki === wfWikiID() ) {
 701                         return 'local'; // the current wiki
 702                 } elseif ( $clusterWiki !== false ) {
 703                         return 'remote'; // another wiki in this cluster/farm
 704                 }
 705
 706                 return 'external';
 707         }
 708
 709         /**
 710          * This function does work that can be done *after* the
 711          * user gets the HTTP response so they don't block on it
 712          *
 713          * This manages deferred updates, job insertion,
 714          * final commit, and the logging of profiling data
 715          *
 716          * @param string $mode Use 'fast' to always skip job running
 717          * @since 1.26
 718          */
 719         public function doPostOutputShutdown( $mode = 'normal' ) {
 720                 // Perform the last synchronous operations...
 721                 try {
 722                         // Record backend request timing
 723                         $timing = $this->context->getTiming();
 724                         $timing->mark( 'requestShutdown' );
 725                         // Show visible profiling data if enabled (which cannot be post-send)
 726                         Profiler::instance()->logDataPageOutputOnly();
 727                 } catch ( Exception $e ) {
 728                         // An error may already have been shown in run(), so just log it to be safe
 729                         MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 730                 }
 731
 732                 // Disable WebResponse setters for post-send processing (T191537).
 733                 WebResponse::disableForPostSend();
 734
 735                 $blocksHttpClient = true;
 736                 // Defer everything else if possible...
 737                 $callback = function () use ( $mode, &$blocksHttpClient ) {
 738                         try {
 739                                 $this->restInPeace( $mode, $blocksHttpClient );
 740                         } catch ( Exception $e ) {
 741                                 // If this is post-send, then displaying errors can cause broken HTML
 742                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 743                         }
 744                 };
 745
 746                 if ( function_exists( 'register_postsend_function' ) ) {
 747                         // https://github.com/facebook/hhvm/issues/1230
 748                         register_postsend_function( $callback );
 749                         /** @noinspection PhpUnusedLocalVariableInspection */
 750                         $blocksHttpClient = false;
 751                 } else {
 752                         if ( function_exists( 'fastcgi_finish_request' ) ) {
 753                                 fastcgi_finish_request();
 754                                 /** @noinspection PhpUnusedLocalVariableInspection */
 755                                 $blocksHttpClient = false;
 756                         } else {
 757                                 // Either all DB and deferred updates should happen or none.
 758                                 // The latter should not be cancelled due to client disconnect.
 759                                 ignore_user_abort( true );
 760                         }
 761
 762                         $callback();
 763                 }
 764         }
 765
 766         private function main() {
 767                 global $wgTitle;
 768
 769                 $output = $this->context->getOutput();
 770                 $request = $this->context->getRequest();
 771
 772                 // Send Ajax requests to the Ajax dispatcher.
 773                 if ( $request->getVal( 'action' ) === 'ajax' ) {
 774                         // Set a dummy title, because $wgTitle == null might break things
 775                         $title = Title::makeTitle( NS_SPECIAL, 'Badtitle/performing an AJAX call in '
 776                                 . __METHOD__
 777                         );
 778                         $this->context->setTitle( $title );
 779                         $wgTitle = $title;
 780
 781                         $dispatcher = new AjaxDispatcher( $this->config );
 782                         $dispatcher->performAction( $this->context->getUser() );
 783
 784                         return;
 785                 }
 786
 787                 // Get title from request parameters,
 788                 // is set on the fly by parseTitle the first time.
 789                 $title = $this->getTitle();
 790                 $action = $this->getAction();
 791                 $wgTitle = $title;
 792
 793                 // Set DB query expectations for this HTTP request
 794                 $trxLimits = $this->config->get( 'TrxProfilerLimits' );
 795                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 796                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
 797                 if ( $request->hasSafeMethod() ) {
 798                         $trxProfiler->setExpectations( $trxLimits['GET'], __METHOD__ );
 799                 } else {
 800                         $trxProfiler->setExpectations( $trxLimits['POST'], __METHOD__ );
 801                 }
 802
 803                 // If the user has forceHTTPS set to true, or if the user
 804                 // is in a group requiring HTTPS, or if they have the HTTPS
 805                 // preference set, redirect them to HTTPS.
 806                 // Note: Do this after $wgTitle is setup, otherwise the hooks run from
 807                 // isLoggedIn() will do all sorts of weird stuff.
 808                 if (
 809                         $request->getProtocol() == 'http' &&
 810                         // switch to HTTPS only when supported by the server
 811                         preg_match( '#^https://#', wfExpandUrl( $request->getRequestURL(), PROTO_HTTPS ) ) &&
 812                         (
 813                                 $request->getSession()->shouldForceHTTPS() ||
 814                                 // Check the cookie manually, for paranoia
 815                                 $request->getCookie( 'forceHTTPS', '' ) ||
 816                                 // check for prefixed version that was used for a time in older MW versions
 817                                 $request->getCookie( 'forceHTTPS' ) ||
 818                                 // Avoid checking the user and groups unless it's enabled.
 819                                 (
 820                                         $this->context->getUser()->isLoggedIn()
 821                                         && $this->context->getUser()->requiresHTTPS()
 822                                 )
 823                         )
 824                 ) {
 825                         $oldUrl = $request->getFullRequestURL();
 826                         $redirUrl = preg_replace( '#^http://#', 'https://', $oldUrl );
 827
 828                         // ATTENTION: This hook is likely to be removed soon due to overall design of the system.
 829                         if ( Hooks::run( 'BeforeHttpsRedirect', [ $this->context, &$redirUrl ] ) ) {
 830                                 if ( $request->wasPosted() ) {
 831                                         // This is weird and we'd hope it almost never happens. This
 832                                         // means that a POST came in via HTTP and policy requires us
 833                                         // redirecting to HTTPS. It's likely such a request is going
 834                                         // to fail due to post data being lost, but let's try anyway
 835                                         // and just log the instance.
 836
 837                                         // @todo FIXME: See if we could issue a 307 or 308 here, need
 838                                         // to see how clients (automated & browser) behave when we do
 839                                         wfDebugLog( 'RedirectedPosts', "Redirected from HTTP to HTTPS: $oldUrl" );
 840                                 }
 841                                 // Setup dummy Title, otherwise OutputPage::redirect will fail
 842                                 $title = Title::newFromText( 'REDIR', NS_MAIN );
 843                                 $this->context->setTitle( $title );
 844                                 // Since we only do this redir to change proto, always send a vary header
 845                                 $output->addVaryHeader( 'X-Forwarded-Proto' );
 846                                 $output->redirect( $redirUrl );
 847                                 $output->output();
 848
 849                                 return;
 850                         }
 851                 }
 852
 853                 if ( $title->canExist() && HTMLFileCache::useFileCache( $this->context ) ) {
 854                         // Try low-level file cache hit
 855                         $cache = new HTMLFileCache( $title, $action );
 856                         if ( $cache->isCacheGood( /* Assume up to date */ ) ) {
 857                                 // Check incoming headers to see if client has this cached
 858                                 $timestamp = $cache->cacheTimestamp();
 859                                 if ( !$output->checkLastModified( $timestamp ) ) {
 860                                         $cache->loadFromFileCache( $this->context );
 861                                 }
 862                                 // Do any stats increment/watchlist stuff, assuming user is viewing the
 863                                 // latest revision (which should always be the case for file cache)
 864                                 $this->context->getWikiPage()->doViewUpdates( $this->context->getUser() );
 865                                 // Tell OutputPage that output is taken care of
 866                                 $output->disable();
 867
 868                                 return;
 869                         }
 870                 }
 871
 872                 // Actually do the work of the request and build up any output
 873                 $this->performRequest();
 874
 875                 // GUI-ify and stash the page output in MediaWiki::doPreOutputCommit() while
 876                 // ChronologyProtector synchronizes DB positions or replicas across all datacenters.
 877                 $buffer = null;
 878                 $outputWork = function () use ( $output, &$buffer ) {
 879                         if ( $buffer === null ) {
 880                                 $buffer = $output->output( true );
 881                         }
 882
 883                         return $buffer;
 884                 };
 885
 886                 // Now commit any transactions, so that unreported errors after
 887                 // output() don't roll back the whole DB transaction and so that
 888                 // we avoid having both success and error text in the response
 889                 $this->doPreOutputCommit( $outputWork );
 890
 891                 // Now send the actual output
 892                 print $outputWork();
 893         }
 894
 895         /**
 896          * Ends this task peacefully
 897          * @param string $mode Use 'fast' to always skip job running
 898          * @param bool $blocksHttpClient Whether this blocks an HTTP response to a client
 899          */
 900         public function restInPeace( $mode = 'fast', $blocksHttpClient = true ) {
 901                 $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 902                 // Assure deferred updates are not in the main transaction
 903                 $lbFactory->commitMasterChanges( __METHOD__ );
 904
 905                 // Loosen DB query expectations since the HTTP client is unblocked
 906                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
 907                 $trxProfiler->resetExpectations();
 908                 $trxProfiler->setExpectations(
 909                         $this->context->getRequest()->hasSafeMethod()
 910                                 ? $this->config->get( 'TrxProfilerLimits' )['PostSend-GET']
 911                                 : $this->config->get( 'TrxProfilerLimits' )['PostSend-POST'],
 912                         __METHOD__
 913                 );
 914
 915                 // Important: this must be the last deferred update added (T100085, T154425)
 916                 DeferredUpdates::addCallableUpdate( [ JobQueueGroup::class, 'pushLazyJobs' ] );
 917
 918                 // Do any deferred jobs; preferring to run them now if a client will not wait on them
 919                 DeferredUpdates::doUpdates( $blocksHttpClient ? 'enqueue' : 'run' );
 920
 921                 // Now that everything specific to this request is done,
 922                 // try to occasionally run jobs (if enabled) from the queues
 923                 if ( $mode === 'normal' ) {
 924                         $this->triggerJobs();
 925                 }
 926
 927                 // Log profiling data, e.g. in the database or UDP
 928                 wfLogProfilingData();
 929
 930                 // Commit and close up!
 931                 $lbFactory->commitMasterChanges( __METHOD__ );
 932                 $lbFactory->shutdown( LBFactory::SHUTDOWN_NO_CHRONPROT );
 933
 934                 wfDebug( "Request ended normally\n" );
 935         }
 936
 937         /**
 938          * Send out any buffered statsd data according to sampling rules
 939          *
 940          * @param IBufferingStatsdDataFactory $stats
 941          * @param Config $config
 942          * @throws ConfigException
 943          * @since 1.31
 944          */
 945         public static function emitBufferedStatsdData(
 946                 IBufferingStatsdDataFactory $stats, Config $config
 947         ) {
 948                 if ( $config->get( 'StatsdServer' ) && $stats->hasData() ) {
 949                         try {
 950                                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
 951                                 $statsdHost = $statsdServer[0];
 952                                 $statsdPort = $statsdServer[1] ?? 8125;
 953                                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
 954                                 $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
 955                                 $statsdClient->setSamplingRates( $config->get( 'StatsdSamplingRates' ) );
 956                                 $statsdClient->send( $stats->getData() );
 957
 958                                 $stats->clearData(); // empty buffer for the next round
 959                         } catch ( Exception $ex ) {
 960                                 MWExceptionHandler::logException( $ex );
 961                         }
 962                 }
 963         }
 964
 965         /**
 966          * Potentially open a socket and sent an HTTP request back to the server
 967          * to run a specified number of jobs. This registers a callback to cleanup
 968          * the socket once it's done.
 969          */
 970         public function triggerJobs() {
 971                 $jobRunRate = $this->config->get( 'JobRunRate' );
 972                 if ( $this->getTitle()->isSpecial( 'RunJobs' ) ) {
 973                         return; // recursion guard
 974                 } elseif ( $jobRunRate <= 0 || wfReadOnly() ) {
 975                         return;
 976                 }
 977
 978                 if ( $jobRunRate < 1 ) {
 979                         $max = mt_getrandmax();
 980                         if ( mt_rand( 0, $max ) > $max * $jobRunRate ) {
 981                                 return; // the higher the job run rate, the less likely we return here
 982                         }
 983                         $n = 1;
 984                 } else {
 985                         $n = intval( $jobRunRate );
 986                 }
 987
 988                 $logger = LoggerFactory::getInstance( 'runJobs' );
 989
 990                 try {
 991                         if ( $this->config->get( 'RunJobsAsync' ) ) {
 992                                 // Send an HTTP request to the job RPC entry point if possible
 993                                 $invokedWithSuccess = $this->triggerAsyncJobs( $n, $logger );
 994                                 if ( !$invokedWithSuccess ) {
 995                                         // Fall back to blocking on running the job(s)
 996                                         $logger->warning( "Jobs switched to blocking; Special:RunJobs disabled" );
 997                                         $this->triggerSyncJobs( $n, $logger );
 998                                 }
 999                         } else {
1000                                 $this->triggerSyncJobs( $n, $logger );
1001                         }
1002                 } catch ( JobQueueError $e ) {
1003                         // Do not make the site unavailable (T88312)
1004                         MWExceptionHandler::logException( $e );
1005                 }
1006         }
1007
1008         /**
1009          * @param int $n Number of jobs to try to run
1010          * @param LoggerInterface $runJobsLogger
1011          */
1012         private function triggerSyncJobs( $n, LoggerInterface $runJobsLogger ) {
1013                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1014                 $old = $trxProfiler->setSilenced( true );
1015                 try {
1016                         $runner = new JobRunner( $runJobsLogger );
1017                         $runner->run( [ 'maxJobs' => $n ] );
1018                 } finally {
1019                         $trxProfiler->setSilenced( $old );
1020                 }
1021         }
1022
1023         /**
1024          * @param int $n Number of jobs to try to run
1025          * @param LoggerInterface $runJobsLogger
1026          * @return bool Success
1027          */
1028         private function triggerAsyncJobs( $n, LoggerInterface $runJobsLogger ) {
1029                 // Do not send request if there are probably no jobs
1030                 $group = JobQueueGroup::singleton();
1031                 if ( !$group->queuesHaveJobs( JobQueueGroup::TYPE_DEFAULT ) ) {
1032                         return true;
1033                 }
1034
1035                 $query = [ 'title' => 'Special:RunJobs',
1036                         'tasks' => 'jobs', 'maxjobs' => $n, 'sigexpiry' => time() + 5 ];
1037                 $query['signature'] = SpecialRunJobs::getQuerySignature(
1038                         $query, $this->config->get( 'SecretKey' ) );
1039
1040                 $errno = $errstr = null;
1041                 $info = wfParseUrl( $this->config->get( 'CanonicalServer' ) );
1042                 $host = $info ? $info['host'] : null;
1043                 $port = 80;
1044                 if ( isset( $info['scheme'] ) && $info['scheme'] == 'https' ) {
1045                         $host = "tls://" . $host;
1046                         $port = 443;
1047                 }
1048                 if ( isset( $info['port'] ) ) {
1049                         $port = $info['port'];
1050                 }
1051
1052                 Wikimedia\suppressWarnings();
1053                 $sock = $host ? fsockopen(
1054                         $host,
1055                         $port,
1056                         $errno,
1057                         $errstr,
1058                         // If it takes more than 100ms to connect to ourselves there is a problem...
1059                         0.100
1060                 ) : false;
1061                 Wikimedia\restoreWarnings();
1062
1063                 $invokedWithSuccess = true;
1064                 if ( $sock ) {
1065                         $special = MediaWikiServices::getInstance()->getSpecialPageFactory()->
1066                                 getPage( 'RunJobs' );
1067                         $url = $special->getPageTitle()->getCanonicalURL( $query );
1068                         $req = (
1069                                 "POST $url HTTP/1.1\r\n" .
1070                                 "Host: {$info['host']}\r\n" .
1071                                 "Connection: Close\r\n" .
1072                                 "Content-Length: 0\r\n\r\n"
1073                         );
1074
1075                         $runJobsLogger->info( "Running $n job(s) via '$url'" );
1076                         // Send a cron API request to be performed in the background.
1077                         // Give up if this takes too long to send (which should be rare).
1078                         stream_set_timeout( $sock, 2 );
1079                         $bytes = fwrite( $sock, $req );
1080                         if ( $bytes !== strlen( $req ) ) {
1081                                 $invokedWithSuccess = false;
1082                                 $runJobsLogger->error( "Failed to start cron API (socket write error)" );
1083                         } else {
1084                                 // Do not wait for the response (the script should handle client aborts).
1085                                 // Make sure that we don't close before that script reaches ignore_user_abort().
1086                                 $start = microtime( true );
1087                                 $status = fgets( $sock );
1088                                 $sec = microtime( true ) - $start;
1089                                 if ( !preg_match( '#^HTTP/\d\.\d 202 #', $status ) ) {
1090                                         $invokedWithSuccess = false;
1091                                         $runJobsLogger->error( "Failed to start cron API: received '$status' ($sec)" );
1092                                 }
1093                         }
1094                         fclose( $sock );
1095                 } else {
1096                         $invokedWithSuccess = false;
1097                         $runJobsLogger->error( "Failed to start cron API (socket error $errno): $errstr" );
1098                 }
1099
1100                 return $invokedWithSuccess;
1101         }
1102 }