mediawiki-extensions-SpamBl.../BaseBlacklist.php
Aaron Schulz d29aca496a Improve use of edit stash hook to check links
In the common case where no banned links were found, cache this
information to skip the checks on save.

Change-Id: I5f936622bc62d9fc905edaa2a69f52388c047d10
2016-07-10 16:17:51 -07:00

419 lines
11 KiB
PHP

<?php
/**
* Base class for different kinds of blacklists
*/
abstract class BaseBlacklist {
/**
* Array of blacklist sources
*
* @var array
*/
public $files = array();
/**
* Array containing regexes to test against
*
* @var bool|array
*/
protected $regexes = false;
/**
* Chance of receiving a warning when the filter is hit
*
* @var int
*/
public $warningChance = 100;
/**
* @var int
*/
public $warningTime = 600;
/**
* @var int
*/
public $expiryTime = 900;
/**
* Array containing blacklists that extend BaseBlacklist
*
* @var array
*/
private static $blacklistTypes = array(
'spam' => 'SpamBlacklist',
'email' => 'EmailBlacklist',
);
/**
* Array of blacklist instances
*
* @var array
*/
private static $instances = array();
/**
* Constructor
*
* @param array $settings
*/
function __construct( $settings = array() ) {
foreach ( $settings as $name => $value ) {
$this->$name = $value;
}
}
/**
* @param array $links
* @param Title $title
* @param bool $preventLog
* @return mixed
*/
abstract public function filter( array $links, Title $title, $preventLog = false );
/**
* Adds a blacklist class to the registry
*
* @param $type string
* @param $class string
*/
public static function addBlacklistType( $type, $class ) {
self::$blacklistTypes[$type] = $class;
}
/**
* Return the array of blacklist types currently defined
*
* @return array
*/
public static function getBlacklistTypes() {
return self::$blacklistTypes;
}
/**
* Returns an instance of the given blacklist
*
* @param $type string Code for the blacklist
* @return BaseBlacklist
* @throws Exception
*/
public static function getInstance( $type ) {
if ( !isset( self::$blacklistTypes[$type] ) ) {
throw new Exception( "Invalid blacklist type '$type' passed to " . __METHOD__ );
}
if ( !isset( self::$instances[$type] ) ) {
global $wgBlacklistSettings;
// Prevent notices
if ( !isset( $wgBlacklistSettings[$type] ) ) {
$wgBlacklistSettings[$type] = array();
}
$class = self::$blacklistTypes[$type];
self::$instances[$type] = new $class( $wgBlacklistSettings[$type] );
}
return self::$instances[$type];
}
/**
* Returns the code for the blacklist implementation
*
* @return string
*/
abstract protected function getBlacklistType();
/**
* Check if the given local page title is a spam regex source.
*
* @param Title $title
* @return bool
*/
public static function isLocalSource( Title $title ) {
global $wgDBname, $wgBlacklistSettings;
if( $title->getNamespace() == NS_MEDIAWIKI ) {
$sources = array();
foreach ( self::$blacklistTypes as $type => $class ) {
$type = ucfirst( $type );
$sources += array(
"$type-blacklist",
"$type-whitelist"
);
}
if( in_array( $title->getDBkey(), $sources ) ) {
return true;
}
}
$thisHttp = wfExpandUrl( $title->getFullUrl( 'action=raw' ), PROTO_HTTP );
$thisHttpRegex = '/^' . preg_quote( $thisHttp, '/' ) . '(?:&.*)?$/';
$files = array();
foreach ( self::$blacklistTypes as $type => $class ) {
if ( isset( $wgBlacklistSettings[$type]['files'] ) ) {
$files += $wgBlacklistSettings[$type]['files'];
}
}
foreach( $files as $fileName ) {
$matches = array();
if ( preg_match( '/^DB: (\w*) (.*)$/', $fileName, $matches ) ) {
if ( $wgDBname == $matches[1] ) {
if( $matches[2] == $title->getPrefixedDbKey() ) {
// Local DB fetch of this page...
return true;
}
}
} elseif( preg_match( $thisHttpRegex, $fileName ) ) {
// Raw view of this page
return true;
}
}
return false;
}
/**
* Returns the type of blacklist from the given title
*
* @param Title $title
* @return bool|string
*/
public static function getTypeFromTitle( Title $title ) {
$types = array_map( 'preg_quote', array_keys( self::$blacklistTypes ), array( '/' ) );
$regex = '/(' . implode( '|', $types ). ')-(?:Blacklist|Whitelist)/';
if ( preg_match( $regex, $title->getDBkey(), $m ) ) {
return strtolower( $m[1] );
}
return false;
}
/**
* Fetch local and (possibly cached) remote blacklists.
* Will be cached locally across multiple invocations.
* @return array set of regular expressions, potentially empty.
*/
function getBlacklists() {
if( $this->regexes === false ) {
$this->regexes = array_merge(
$this->getLocalBlacklists(),
$this->getSharedBlacklists() );
}
return $this->regexes;
}
/**
* Returns the local blacklist
*
* @return array Regular expressions
*/
public function getLocalBlacklists() {
$that = $this;
$type = $this->getBlacklistType();
return ObjectCache::getMainWANInstance()->getWithSetCallback(
wfMemcKey( 'spamblacklist', $type, 'blacklist-regex' ),
$this->expiryTime,
function () use ( $that, $type ) {
return SpamRegexBatch::regexesFromMessage( "{$type}-blacklist", $that );
}
);
}
/**
* Returns the (local) whitelist
*
* @return array Regular expressions
*/
public function getWhitelists() {
$that = $this;
$type = $this->getBlacklistType();
return ObjectCache::getMainWANInstance()->getWithSetCallback(
wfMemcKey( 'spamblacklist', $type, 'whitelist-regex' ),
$this->expiryTime,
function () use ( $that, $type ) {
return SpamRegexBatch::regexesFromMessage( "{$type}-whitelist", $that );
}
);
}
/**
* Fetch (possibly cached) remote blacklists.
* @return array
*/
function getSharedBlacklists() {
$listType = $this->getBlacklistType();
wfDebugLog( 'SpamBlacklist', "Loading $listType regex..." );
if ( count( $this->files ) == 0 ){
# No lists
wfDebugLog( 'SpamBlacklist', "no files specified\n" );
return array();
}
$miss = false;
$that = $this;
$regexes = ObjectCache::getMainWANInstance()->getWithSetCallback(
// This used to be cached per-site, but that could be bad on a shared
// server where not all wikis have the same configuration.
wfMemcKey( 'spamblacklist', $listType, 'shared-blacklist-regex' ),
$this->expiryTime,
function () use ( $that, &$miss ) {
$miss = true;
return $that->buildSharedBlacklists();
}
);
if ( !$miss ) {
wfDebugLog( 'SpamBlacklist', "Got shared spam regexes from cache\n" );
}
return $regexes;
}
/**
* Clear all primary blacklist cache keys
*
* @note: this method is unused atm
*/
function clearCache() {
$listType = $this->getBlacklistType();
$cache = ObjectCache::getMainWANInstance();
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'shared-blacklist-regex' ) );
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'blacklist-regex' ) );
$cache->delete( wfMemcKey( 'spamblacklist', $listType, 'whitelist-regex' ) );
wfDebugLog( 'SpamBlacklist', "$listType blacklist local cache cleared.\n" );
}
function buildSharedBlacklists() {
$regexes = array();
$listType = $this->getBlacklistType();
# Load lists
wfDebugLog( 'SpamBlacklist', "Constructing $listType blacklist\n" );
foreach ( $this->files as $fileName ) {
$matches = array();
if ( preg_match( '/^DB: ([\w-]*) (.*)$/', $fileName, $matches ) ) {
$text = $this->getArticleText( $matches[1], $matches[2] );
} elseif ( preg_match( '/^(https?:)?\/\//', $fileName ) ) {
$text = $this->getHttpText( $fileName );
} else {
$text = file_get_contents( $fileName );
wfDebugLog( 'SpamBlacklist', "got from file $fileName\n" );
}
// Build a separate batch of regexes from each source.
// While in theory we could squeeze a little efficiency
// out of combining multiple sources in one regex, if
// there's a bad line in one of them we'll gain more
// from only having to break that set into smaller pieces.
$regexes = array_merge( $regexes,
SpamRegexBatch::regexesFromText( $text, $this, $fileName ) );
}
return $regexes;
}
function getHttpText( $fileName ) {
global $wgDBname, $messageMemc;
$listType = $this->getBlacklistType();
# HTTP request
# To keep requests to a minimum, we save results into $messageMemc, which is
# similar to $wgMemc except almost certain to exist. By default, it is stored
# in the database
#
# There are two keys, when the warning key expires, a random thread will refresh
# the real key. This reduces the chance of multiple requests under high traffic
# conditions.
$key = "{$listType}_blacklist_file:$fileName";
$warningKey = "$wgDBname:{$listType}filewarning:$fileName";
$httpText = $messageMemc->get( $key );
$warning = $messageMemc->get( $warningKey );
if ( !is_string( $httpText ) || ( !$warning && !mt_rand( 0, $this->warningChance ) ) ) {
wfDebugLog( 'SpamBlacklist', "Loading $listType blacklist from $fileName\n" );
$httpText = Http::get( $fileName );
if( $httpText === false ) {
wfDebugLog( 'SpamBlacklist', "Error loading $listType blacklist from $fileName\n" );
}
$messageMemc->set( $warningKey, 1, $this->warningTime );
$messageMemc->set( $key, $httpText, $this->expiryTime );
} else {
wfDebugLog( 'SpamBlacklist', "Got $listType blacklist from HTTP cache for $fileName\n" );
}
return $httpText;
}
/**
* Fetch an article from this or another local MediaWiki database.
* This is probably *very* fragile, and shouldn't be used perhaps.
*
* @param string $wiki
* @param string $article
* @return string
*/
function getArticleText( $wiki, $article ) {
wfDebugLog( 'SpamBlacklist',
"Fetching {$this->getBlacklistType()} blacklist from '$article' on '$wiki'...\n" );
$title = Title::newFromText( $article );
// Load all the relevant tables from the correct DB.
// This assumes that old_text is the actual text or
// that the external store system is at least unified.
$row = wfGetDB( DB_SLAVE, array(), $wiki )->selectRow(
array( 'page', 'revision', 'text' ),
array_merge(
Revision::selectFields(),
Revision::selectPageFields(),
Revision::selectTextFields()
),
array(
'page_namespace' => $title->getNamespace(), // assume NS IDs match
'page_title' => $title->getDBkey(), // assume same case rules
'rev_id=page_latest',
'old_id=rev_text_id'
),
__METHOD__
);
return $row ? Revision::newFromRow( $row )->getText() : false;
}
/**
* Returns the start of the regex for matches
*
* @return string
*/
public function getRegexStart() {
return '/[a-z0-9_\-.]*';
}
/**
* Returns the end of the regex for matches
*
* @param $batchSize
* @return string
*/
public function getRegexEnd( $batchSize ) {
return ($batchSize > 0 ) ? '/Sim' : '/im';
}
/**
* @param Title $title
* @param string[] $entries
*/
public function warmCachesForFilter( Title $title, array $entries ) {
// subclass this
}
}