mediawiki-extensions-SpamBl.../includes/SpamBlacklist.php
Aaron Schulz f8b957167e Hash the title in "blacklist" cache keys
This avoids "Key contains invalid characters" in some cases.

Change-Id: I720c5e89e38b7da69c87134d1ff51787b4fa5c0c
2018-07-10 12:38:53 +01:00

349 lines
9.7 KiB
PHP
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<?php
if ( !defined( 'MEDIAWIKI' ) ) {
exit;
}
use \MediaWiki\MediaWikiServices;
use Wikimedia\Rdbms\Database;
class SpamBlacklist extends BaseBlacklist {
const STASH_TTL = 180;
const STASH_AGE_DYING = 150;
/**
* Changes to external links, for logging purposes
* @var array[]
*/
private $urlChangeLog = [];
/**
* Returns the code for the blacklist implementation
*
* @return string
*/
protected function getBlacklistType() {
return 'spam';
}
/**
* Apply some basic anti-spoofing to the links before they get filtered,
* see @bug 12896
*
* @param string $text
*
* @return string
*/
protected function antiSpoof( $text ) {
$text = str_replace( '', '.', $text );
return $text;
}
/**
* @param string[] $links An array of links to check against the blacklist
* @param Title|null $title The title of the page to which the filter shall be applied.
* This is used to load the old links already on the page, so
* the filter is only applied to links that got added. If not given,
* the filter is applied to all $links.
* @param bool $preventLog Whether to prevent logging of hits. Set to true when
* the action is testing the links rather than attempting to save them
* (e.g. the API spamblacklist action)
* @param string $mode Either 'check' or 'stash'
*
* @return string[]|bool Matched text(s) if the edit should not be allowed; false otherwise
*/
function filter( array $links, Title $title = null, $preventLog = false, $mode = 'check' ) {
$statsd = MediaWikiServices::getInstance()->getStatsdDataFactory();
$cache = ObjectCache::getLocalClusterInstance();
// If there are no new links, and we are logging,
// mark all of the current links as being removed.
if ( !$links && $this->isLoggingEnabled() ) {
$this->logUrlChanges( $this->getCurrentLinks( $title ), [], [] );
}
if ( !$links ) {
return false;
}
sort( $links );
$key = $cache->makeKey(
'blacklist',
$this->getBlacklistType(),
'pass',
sha1( implode( "\n", $links ) ),
md5( (string)$title )
);
// Skip blacklist checks if nothing matched during edit stashing...
$knownNonMatchAsOf = $cache->get( $key );
if ( $mode === 'check' ) {
if ( $knownNonMatchAsOf ) {
$statsd->increment( 'spamblacklist.check-stash.hit' );
return false;
} else {
$statsd->increment( 'spamblacklist.check-stash.miss' );
}
} elseif ( $mode === 'stash' ) {
if ( $knownNonMatchAsOf && ( time() - $knownNonMatchAsOf ) < self::STASH_AGE_DYING ) {
return false; // OK; not about to expire soon
}
}
$blacklists = $this->getBlacklists();
$whitelists = $this->getWhitelists();
if ( count( $blacklists ) ) {
// poor man's anti-spoof, see bug 12896
$newLinks = array_map( [ $this, 'antiSpoof' ], $links );
$oldLinks = [];
if ( $title !== null ) {
$oldLinks = $this->getCurrentLinks( $title );
$addedLinks = array_diff( $newLinks, $oldLinks );
} else {
// can't load old links, so treat all links as added.
$addedLinks = $newLinks;
}
wfDebugLog( 'SpamBlacklist', "Old URLs: " . implode( ', ', $oldLinks ) );
wfDebugLog( 'SpamBlacklist', "New URLs: " . implode( ', ', $newLinks ) );
wfDebugLog( 'SpamBlacklist', "Added URLs: " . implode( ', ', $addedLinks ) );
if ( !$preventLog ) {
$this->logUrlChanges( $oldLinks, $newLinks, $addedLinks );
}
$links = implode( "\n", $addedLinks );
# Strip whitelisted URLs from the match
if ( is_array( $whitelists ) ) {
wfDebugLog( 'SpamBlacklist', "Excluding whitelisted URLs from " . count( $whitelists ) .
" regexes: " . implode( ', ', $whitelists ) . "\n" );
foreach ( $whitelists as $regex ) {
wfSuppressWarnings();
$newLinks = preg_replace( $regex, '', $links );
wfRestoreWarnings();
if ( is_string( $newLinks ) ) {
// If there wasn't a regex error, strip the matching URLs
$links = $newLinks;
}
}
}
# Do the match
wfDebugLog( 'SpamBlacklist', "Checking text against " . count( $blacklists ) .
" regexes: " . implode( ', ', $blacklists ) . "\n" );
$retVal = false;
foreach ( $blacklists as $regex ) {
wfSuppressWarnings();
$matches = [];
$check = ( preg_match_all( $regex, $links, $matches ) > 0 );
wfRestoreWarnings();
if ( $check ) {
wfDebugLog( 'SpamBlacklist', "Match!\n" );
global $wgRequest;
$ip = $wgRequest->getIP();
$fullUrls = [];
$fullLineRegex = substr( $regex, 0, strrpos( $regex, '/' ) ) . '.*/Sim';
preg_match_all( $fullLineRegex, $links, $fullUrls );
$imploded = implode( ' ', $fullUrls[0] );
wfDebugLog( 'SpamBlacklistHit', "$ip caught submitting spam: $imploded\n" );
if ( !$preventLog ) {
$this->logFilterHit( $title, $imploded ); // Log it
}
if ( $retVal === false ) {
$retVal = [];
}
$retVal = array_merge( $retVal, $fullUrls[1] );
}
}
if ( is_array( $retVal ) ) {
$retVal = array_unique( $retVal );
}
} else {
$retVal = false;
}
if ( $retVal === false ) {
// Cache the typical negative results
$cache->set( $key, time(), self::STASH_TTL );
if ( $mode === 'stash' ) {
$statsd->increment( 'spamblacklist.check-stash.store' );
}
}
return $retVal;
}
public function isLoggingEnabled() {
global $wgSpamBlacklistEventLogging;
return $wgSpamBlacklistEventLogging && class_exists( 'EventLogging' );
}
/**
* Diff added/removed urls and generate events for them
*
* @param string[] $oldLinks
* @param string[] $newLinks
* @param string[] $addedLinks
*/
public function logUrlChanges( $oldLinks, $newLinks, $addedLinks ) {
if ( !$this->isLoggingEnabled() ) {
return;
}
$removedLinks = array_diff( $oldLinks, $newLinks );
foreach ( $addedLinks as $url ) {
$this->logUrlChange( $url, 'insert' );
}
foreach ( $removedLinks as $url ) {
$this->logUrlChange( $url, 'remove' );
}
}
/**
* Actually push the url change events post-save
*
* @param User $user
* @param Title $title
* @param int $revId
*/
public function doLogging( User $user, Title $title, $revId ) {
if ( !$this->isLoggingEnabled() ) {
return;
}
$baseInfo = [
'revId' => $revId,
'pageId' => $title->getArticleID(),
'pageNamespace' => $title->getNamespace(),
'userId' => $user->getId(),
'userText' => $user->getName(),
];
$changes = $this->urlChangeLog;
// Empty the changes queue in case this function gets called more than once
$this->urlChangeLog = [];
DeferredUpdates::addCallableUpdate( function () use ( $changes, $baseInfo ) {
foreach ( $changes as $change ) {
EventLogging::logEvent(
'ExternalLinksChange',
15716074,
$baseInfo + $change
);
}
} );
}
/**
* Queue log data about change for a url addition or removal
*
* @param string $url
* @param string $action 'insert' or 'remove'
*/
private function logUrlChange( $url, $action ) {
$parsed = wfParseUrl( $url );
if ( !isset( $parsed['host'] ) ) {
wfDebugLog( 'SpamBlacklist', "Unable to parse $url" );
return;
}
$info = [
'action' => $action,
'protocol' => $parsed['scheme'],
'domain' => $parsed['host'],
'path' => isset( $parsed['path'] ) ? $parsed['path'] : '',
'query' => isset( $parsed['query'] ) ? $parsed['query'] : '',
'fragment' => isset( $parsed['fragment'] ) ? $parsed['fragment'] : '',
];
$this->urlChangeLog[] = $info;
}
/**
* Look up the links currently in the article, so we can
* ignore them on a second run.
*
* WARNING: I can add more *of the same link* with no problem here.
* @param Title $title
* @return array
*/
function getCurrentLinks( Title $title ) {
$cache = ObjectCache::getMainWANInstance();
return $cache->getWithSetCallback(
// Key is warmed via warmCachesForFilter() from ApiStashEdit
$cache->makeKey( 'external-link-list', $title->getLatestRevID() ),
$cache::TTL_MINUTE,
function ( $oldValue, &$ttl, array &$setOpts ) use ( $title ) {
$dbr = wfGetDB( DB_REPLICA );
$setOpts += Database::getCacheSetOptions( $dbr );
return $dbr->selectFieldValues(
'externallinks',
'el_to',
[ 'el_from' => $title->getArticleID() ], // should be zero queries
__METHOD__
);
}
);
}
public function warmCachesForFilter( Title $title, array $entries ) {
$this->filter( $entries, $title, true /* no logging */, 'stash' );
}
/**
* Returns the start of the regex for matches
*
* @return string
*/
public function getRegexStart() {
return '/(?:https?:)?\/\/+[a-z0-9_\-.]*(';
}
/**
* Returns the end of the regex for matches
*
* @param int $batchSize
* @return string
*/
public function getRegexEnd( $batchSize ) {
return ')' . parent::getRegexEnd( $batchSize );
}
/**
* Logs the filter hit to Special:Log if
* $wgLogSpamBlacklistHits is enabled.
*
* @param Title $title
* @param string $url URL that the user attempted to add
*/
public function logFilterHit( $title, $url ) {
global $wgUser, $wgLogSpamBlacklistHits;
if ( $wgLogSpamBlacklistHits ) {
$logEntry = new ManualLogEntry( 'spamblacklist', 'hit' );
$logEntry->setPerformer( $wgUser );
$logEntry->setTarget( $title );
$logEntry->setParameters( [
'4::url' => $url,
] );
$logid = $logEntry->insert();
$log = new LogPage( 'spamblacklist' );
if ( $log->isRestricted() ) {
// Make sure checkusers can see this action if the log is restricted
// (which is the default)
if ( ExtensionRegistry::getInstance()->isLoaded( 'CheckUser' )
&& class_exists( 'CheckUserHooks' )
) {
$rc = $logEntry->getRecentChange( $logid );
CheckUserHooks::updateCheckUserData( $rc );
}
} else {
// If the log is unrestricted, publish normally to RC,
// which will also update checkuser
$logEntry->publish( $logid, "rc" );
}
}
}
}