mediawiki-extensions-AbuseF.../AbuseFilter.class.php
Andrew Garrett 016da694a6 Abuse Filter:
* Reimplement tools, starting with a spiffy AJAX expression tester. Didn't bother implementing as non-AJAX, as it's just an extra.
* Change exchange protocol between native parser and PHP app. Resulted in 2-3-fold performance boost.
* Fix minor bug from last night.
2008-08-04 14:27:48 +00:00

539 lines
15 KiB
PHP

<?php
if ( ! defined( 'MEDIAWIKI' ) )
die();
class AbuseFilter {
public static $statsStoragePeriod = 86400;
public static $tokenCache = array();
public static $modifyCache = array();
public static $condLimitEnabled = true;
public static $condCount = 0;
public static function generateUserVars( $user ) {
$vars = array();
// Load all the data we want.
$user->load();
$vars['USER_EDITCOUNT'] = $user->getEditCount();
$vars['USER_AGE'] = time() - wfTimestampOrNull( TS_UNIX, $user->getRegistration() );
$vars['USER_NAME'] = $user->getName();
$vars['USER_GROUPS'] = implode(',', $user->getEffectiveGroups() );
$vars['USER_EMAILCONFIRM'] = $user->getEmailAuthenticationTimestamp();
// More to come
return $vars;
}
public static function ajaxCheckSyntax( $filter ) {
$result = self::checkSyntax( $filter );
$ok = ($result === true);
if ($ok) {
return "OK";
} else {
return "ERR: $result";
}
}
public static function disableConditionLimit() {
// For use in batch scripts and the like
self::$condLimitEnabled = false;
}
public static function generateTitleVars( $title, $prefix ) {
$vars = array();
$vars[$prefix."_ARTICLEID"] = $title->getArticleId();
$vars[$prefix."_NAMESPACE"] = $title->getNamespace();
$vars[$prefix."_TEXT"] = $title->getText();
$vars[$prefix."_PREFIXEDTEXT"] = $title->getPrefixedText();
if ($title->mRestrictionsLoaded) {
// Don't bother if they're unloaded
foreach( $title->mRestrictions as $action => $rights ) {
$rights = count($rights) ? $rights : array();
$vars[$prefix."_RESTRICTIONS_".$action] = implode(',', $rights );
}
}
// Find last 5 authors
$dbr = wfGetDB( DB_SLAVE );
$res = $dbr->select( 'revision', 'distinct rev_user_text', array('rev_page' => $title->getArticleId() ), __METHOD__, array( 'order by' => 'rev_timestamp desc', 'limit' => 10 ) );
$users = array();
while ($user = $dbr->fetchRow($res)) {
$users[] = $user[0];
}
$vars[$prefix."_RECENT_CONTRIBUTORS"] = implode(',', $users);
return $vars;
}
public static function checkSyntax( $filter ) {
global $wgAbuseFilterParserClass;
$parser = new $wgAbuseFilterParserClass;
return $parser->checkSyntax( $filter );
}
public static function evaluateExpression( $expr, $vars = array() ) {
global $wgAbuseFilterParserClass;
$parser = new $wgAbuseFilterParserClass;
$parser->setVars( $vars );
return $parser->evaluateExpression( $expr );
}
public static function ajaxEvaluateExpression( $expr ) {
return self::evaluateExpression( $expr );
}
public static function checkConditions( $conds, $vars ) {
global $wgAbuseFilterParserClass;
wfProfileIn( __METHOD__ );
try {
$parser = new $wgAbuseFilterParserClass;
$parser->setVars( $vars );
$result = $parser->parse( $conds, self::$condCount );
} catch (Exception $excep) {
// Sigh.
$result = false;
}
wfProfileOut( __METHOD__ );
return $result;
}
public static function filterAction( $vars, $title ) {
global $wgUser,$wgMemc;
// Fetch from the database.
$dbr = wfGetDB( DB_SLAVE );
$res = $dbr->select( 'abuse_filter', '*', array( 'af_enabled' => 1 ) );
$blocking_filters = array();
$log_entries = array();
$log_template = array( 'afl_user' => $wgUser->getId(), 'afl_user_text' => $wgUser->getName(),
'afl_var_dump' => serialize( $vars ), 'afl_timestamp' => $dbr->timestamp(wfTimestampNow()),
'afl_namespace' => $title->getNamespace(), 'afl_title' => $title->getDbKey(), 'afl_ip' => wfGetIp() );
$doneActionsByFilter = array();
$filter_matched = array();
while ( $row = $dbr->fetchObject( $res ) ) {
if ( self::checkConditions( $row->af_pattern, $vars ) ) {
$blocking_filters[$row->af_id] = $row;
$newLog = $log_template;
$newLog['afl_filter'] = $row->af_id;
$newLog['afl_action'] = $vars['ACTION'];
$log_entries[] = $newLog;
$doneActionsByFilter[$row->af_id] = array();
$filter_matched[$row->af_id] = true;
} else {
$filter_matched[$row->af_id] = false;
}
}
//// Clean up from checking all the filters
// Don't store stats if the cond limit is disabled.
// It's probably a batch process or similar.
if (!self::$condLimitEnabled)
self::recordStats( $filter_matched );
if (count($blocking_filters) == 0 ) {
// No problems.
return true;
}
// Retrieve the consequences.
$res = $dbr->select( 'abuse_filter_action', '*', array( 'afa_filter' => array_keys( $blocking_filters ) ), __METHOD__, array( "ORDER BY" => " (afa_consequence in ('throttle','warn'))-(afa_consequence in ('disallow')) desc" ) );
// We want throttles, warnings first, as they have a bit of a special treatment. We want disallow last.
$actions_done = array();
$throttled_filters = array();
$display = '';
while ( $row = $dbr->fetchObject( $res ) ) {
// Don't do the same action-parameters twice
$action_key = md5( $row->afa_consequence . $row->afa_parameters );
// Skip if we've already done this action-parameter, or a passive action has sufficed.
$skipAction = ( in_array( $action_key, $actions_done ) || in_array( $row->afa_filter, $throttled_filters ) );
// Don't disallow if we've already done something active. It produces two messages, where one would suffice.
if ($row->afa_consequence == 'disallow' && !$skipAction) {
$doneActiveActions = array_diff( $doneActionsByFilter[$row->afa_filter], array( 'throttle', 'warn' /* passive actions */ ) );
$skipAction = (bool)count($doneActiveActions);
}
if ( !$skipAction ) {
// Unpack parameters
$parameters = explode( "\n", $row->afa_parameters );
// Take the action.
$result = self::takeConsequenceAction( $row->afa_consequence, $parameters, $title, $vars, $display, $continue, $blocking_filters[$row->afa_filter]->af_public_comments );
// Don't do it twice.
$doneActionsByFilter[$row->afa_filter][] = $row->afa_consequence;
$actions_done[] = $action_key;
// Only execute other actions for a filter if that filter's rate limiter has been tripped.
if (!$result) {
$throttled_filters[] = $row->afa_filter;
}
} else {
// Ignore it, until we hit the rate limit.
}
}
$dbw = wfGetDB( DB_MASTER );
// Log it
foreach( $log_entries as $index => $entry ) {
$log_entries[$index]['afl_actions'] = implode( ',', $doneActionsByFilter[$entry['afl_filter']] );
// Increment the hit counter
$dbw->update( 'abuse_filter', array( 'af_hit_count=af_hit_count+1' ), array( 'af_id' => $entry['afl_filter'] ), __METHOD__ );
}
$dbw->insert( 'abuse_filter_log', $log_entries, __METHOD__ );
return $display;
}
public static function takeConsequenceAction( $action, $parameters, $title, $vars, &$display, &$continue, $rule_desc ) {
switch ($action) {
case 'warn':
wfLoadExtensionMessages( 'AbuseFilter' );
if (!$_SESSION['abusefilter-warned']) {
$_SESSION['abusefilter-warned'] = true;
// Threaten them a little bit
if (strlen($parameters[0])) {
$display .= call_user_func_array( 'wfMsgNoTrans', $parameters ) . "\n";
} else {
// Generic message.
$display .= wfMsgNoTrans( 'abusefilter-warning', $rule_desc ) ."<br />\n";
}
return false; // Don't apply the other stuff yet.
} else {
// We already warned them
$_SESSION['abusefilter-warned'] = false;
}
break;
case 'disallow':
wfLoadExtensionMessages( 'AbuseFilter' );
// Don't let them do it
if (strlen($parameters[0])) {
$display .= call_user_func_array( 'wfMsgNoTrans', $parameters ) . "\n";
} else {
// Generic message.
$display .= wfMsgNoTrans( 'abusefilter-disallowed', $rule_desc ) ."<br />\n";
}
break;
case 'block':
wfLoadExtensionMessages( 'AbuseFilter' );
global $wgUser;
$filterUser = AbuseFilter::getFilterUser();
// Create a block.
$block = new Block;
$block->mAddress = $wgUser->getName();
$block->mUser = $wgUser->getId();
$block->mBy = User::idFromName( wfMsgForContent( 'abusefilter-blocker' ) ); // Let's say the site owner blocked them
$block->mByName = wfMsgForContent( 'abusefilter-blocker' );
$block->mReason = wfMsgForContent( 'abusefilter-blockreason', $rule_desc );
$block->mTimestamp = wfTimestampNow();
$block->mEnableAutoblock = 1;
$block->mAngryAutoblock = 1; // Block lots of IPs
$block->mCreateAccount = 1;
$block->mExpiry = 'infinity';
$block->insert();
// Log it
# Prepare log parameters
$logParams = array();
$logParams[] = 'indefinite';
$logParams[] = 'nocreate, angry-autoblock';
$log = new LogPage( 'block' );
$log->addEntry( 'block', Title::makeTitle( NS_USER, $wgUser->getName() ),
wfMsgForContent( 'abusefilter-blockreason', $rule_desc ), $logParams, self::getFilterUser() );
$display .= wfMsgNoTrans( 'abusefilter-blocked-display', $rule_desc ) ."<br />\n";
break;
case 'throttle':
$throttleId = array_shift( $parameters );
list( $rateCount, $ratePeriod ) = explode( ',', array_shift( $parameters ) );
$hitThrottle = false;
// The rest are throttle-types.
foreach( $parameters as $throttleType ) {
$hitThrottle = $hitThrottle || self::isThrottled( $throttleId, $throttleType, $title, $rateCount, $ratePeriod );
}
return $hitThrottle;
break;
case 'degroup':
wfLoadExtensionMessages( 'AbuseFilter' );
global $wgUser;
if (!$wgUser->isAnon()) {
// Remove all groups from the user. Ouch.
$groups = $wgUser->getGroups();
foreach( $groups as $group ) {
$wgUser->removeGroup( $group );
}
$display .= wfMsgNoTrans( 'abusefilter-degrouped', $rule_desc ) ."<br />\n";
// Log it.
$log = new LogPage( 'rights' );
$log->addEntry( 'rights',
$wgUser->getUserPage(),
wfMsgForContent( 'abusefilter-degroupreason', $rule_desc ),
array(
implode( ', ', $groups ),
wfMsgForContent( 'rightsnone' )
)
, self::getFilterUser() );
}
break;
case 'blockautopromote':
global $wgUser, $wgMemc;
if (!$wgUser->isAnon()) {
wfLoadExtensionMessages( 'AbuseFilter' );
$blockPeriod = (int)mt_rand( 3*86400, 7*86400 ); // Block for 3-7 days.
$wgMemc->set( self::autoPromoteBlockKey( $wgUser ), true, $blockPeriod );
$display .= wfMsgNoTrans( 'abusefilter-autopromote-blocked', $rule_desc ) ."<br />\n";
}
break;
case 'flag':
// Do nothing. Here for completeness.
break;
}
return true;
}
public static function isThrottled( $throttleId, $types, $title, $rateCount, $ratePeriod ) {
global $wgMemc;
$key = self::throttleKey( $throttleId, $types, $title );
$count = $wgMemc->get( $key );
if ($count > 0) {
$wgMemc->incr( $key );
if ($count > $rateCount) {
//die( "Hit rate limiter: $count actions, against limit of $rateCount actions in $ratePeriod seconds (key is $key).\n" );
$wgMemc->delete( $key );
return true; // THROTTLED
}
} else {
$wgMemc->add( $key, 1, $ratePeriod );
}
return false; // NOT THROTTLED
}
public static function throttleIdentifier( $type, $title ) {
global $wgUser;
switch ($type) {
case 'ip':
$identifier = wfGetIp();
break;
case 'user':
$identifier = $wgUser->getId();
break;
case 'range':
$identifier = substr(IP::toHex(wfGetIp()),0,4);
break;
case 'creationdate':
$reg = $wgUser->getRegistration();
$identifier = $reg - ($reg % 86400);
break;
case 'editcount':
// Hack for detecting different single-purpose accounts.
$identifier = $wgUser->getEditCount();
break;
case 'site':
return 1;
break;
case 'page':
return $title->getPrefixedText();
break;
}
return $identifier;
}
public static function throttleKey( $throttleId, $type, $title ) {
$identifier = '';
$types = explode(',', $type);
$identifiers = array();
foreach( $types as $subtype ) {
$identifiers[] = self::throttleIdentifier( $subtype, $title );
}
$identifier = implode( ':', $identifiers );
return wfMemcKey( 'abusefilter', 'throttle', $throttleId, $type, $identifier );
}
public static function autoPromoteBlockKey( $user ) {
return wfMemcKey( 'abusefilter', 'block-autopromote', $user->getId() );
}
public static function recordStats( $filters ) {
global $wgAbuseFilterConditionLimit,$wgMemc;
$overflow_triggered = (self::$condCount > $wgAbuseFilterConditionLimit);
$filter_triggered = count($blocking_filters);
$overflow_key = self::filterLimitReachedKey();
$total_key = self::filterUsedKey();
$total = $wgMemc->get( $total_key );
$storage_period = self::$statsStoragePeriod; // One day.
if (!$total || $total > 1000) {
$wgMemc->set( $total_key, 1, $storage_period );
if ($overflow_triggered) {
$wgMemc->set( $overflow_key, 1, $storage_period );
} else {
$wgMemc->set( $overflow_key, 0, $storage_period );
}
$anyMatch = false;
foreach( $filters as $filter => $matched ) {
$filter_key = self::filterMatchesKey( $filter );
if ($matched) {
$anyMatch = true;
$wgMemc->set( $filter_key, 1, $storage_period );
} else {
$wgMemc->set( $filter_key, 0, $storage_period );
}
}
if ($anyMatch) {
$wgMemc->set( self::filterMatchesKey(), 1, $storage_period );
} else {
$wgMemc->set( self::filterMatchesKey(), 0, $storage_period );
}
return;
}
$wgMemc->incr( $total_key );
if ($overflow_triggered) {
$wgMemc->incr( $overflow_key );
}
$anyMatch = false;
global $wgAbuseFilterEmergencyDisableThreshold, $wgAbuseFilterEmergencyDisableCount;
foreach( $filters as $filter => $matched ) {
if ($matched) {
$anyMatch = true;
$match_count = $wgMemc->get( self::filterMatchesKey( $filter ) );
if ($match_count > 0) {
$wgMemc->incr( self::filterMatchesKey( $filter ) );
} else {
$wgMemc->set( self::filterMatchesKey( $filter ), 1, self::$statsStoragePeriod );
}
if ($match_count > $wgAbuseFilterEmergencyDisableCount && ($match_count / $total) > $wgAbuseFilterEmergencyDisableThreshold) {
// More than X matches, constituting more than Y% of last Z edits. Disable it.
$dbw = wfGetDB( DB_MASTER );
$dbw->update( 'abuse_filter', array( 'af_enabled' => 0, 'af_throttled' => 1 ), array( 'af_id' => $filter ), __METHOD__ );
}
}
}
if ($anyMatch) {
$wgMemc->incr( self::filterMatchesKey() );
}
}
public static function filterLimitReachedKey() {
return wfMemcKey( 'abusefilter', 'stats', 'overflow' );
}
public static function filterUsedKey() {
return wfMemcKey( 'abusefilter', 'stats', 'total' );
}
public static function filterMatchesKey( $filter = null ) {
return wfMemcKey( 'abusefilter', 'stats', 'matches', $filter );
}
public static function getFilterUser() {
wfLoadExtensionMessages( 'AbuseFilter' );
$user = User::newFromName( wfMsgForContent( 'abusefilter-blocker' ) );
$user->load();
if ($user->getId() && $user->mPassword == '') {
// Already set up.
return $user;
}
// Not set up. Create it.
if (!$user->getId()) {
$user->addToDatabase();
$user->saveSettings();
} else {
// Take over the account
$user->setPassword( null );
$user->setEmail( null );
$user->saveSettings();
}
# Promote user so it doesn't look too crazy.
$user->addGroup( 'sysop' );
# Increment site_stats.ss_users
$ssu = new SiteStatsUpdate( 0, 0, 0, 0, 1 );
$ssu->doUpdate();
return $user;
}
}