mediawiki-extensions-AbuseF.../AbuseFilter.class.php
2009-01-25 05:12:05 +00:00

674 lines
21 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 $filters = array();
public static $tagsToSet = array();
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 triggerLimiter( $val = 1 ) {
self::$condCount += $val;
global $wgAbuseFilterConditionLimit;
if (self::$condCount > $wgAbuseFilterConditionLimit) {
throw new MWException( "Condition limit reached." );
}
}
public static function disableConditionLimit() {
// For use in batch scripts and the like
self::$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"] = $title->getPrefixedText();
// Use restrictions.
if ($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 ajaxReAutoconfirm( $username ) {
if (!$wgUser->isAllowed('abusefilter-modify')) {
// Don't allow it.
return wfMsg( 'abusefilter-reautoconfirm-notallowed' );
}
$u = User::newFromName( $username );
global $wgMemc;
$k = AbuseFilter::autoPromoteBlockKey($u);
if (!$wgMemc->get( $k ) ) {
return wfMsg( 'abusefilter-reautoconfirm-none' );
}
$wgMemc->delete( $k );
}
public static function ajaxEvaluateExpression( $expr ) {
return self::evaluateExpression( $expr );
}
public static function checkConditions( $conds, $vars, $ignoreError = true ) {
global $wgAbuseFilterParserClass;
wfProfileIn( __METHOD__ );
try {
$parser = new $wgAbuseFilterParserClass;
$parser->setVars( $vars );
$result = $parser->parse( $conds, self::$condCount );
} catch (Exception $excep) {
// Sigh.
$result = false;
if (!$ignoreError) {
throw $excep;
}
}
wfProfileOut( __METHOD__ );
return $result;
}
/** Returns an associative array of filters which were tripped */
public static function checkAllFilters( $vars ) {
// Fetch from the database.
$dbr = wfGetDB( DB_SLAVE );
$res = $dbr->select( 'abuse_filter', '*', array( 'af_enabled' => 1, 'af_deleted' => 0 ) );
while ( $row = $dbr->fetchObject( $res ) ) {
// Store the row somewhere convenient
self::$filters[$row->af_id] = $row;
// Check conditions...
$pattern = trim($row->af_pattern);
if ( self::checkConditions( $pattern, $vars ) ) {
// Record match.
$filter_matched[$row->af_id] = true;
} else {
// Record non-match.
$filter_matched[$row->af_id] = false;
}
}
// Update statistics, and disable filters which are over-blocking.
self::recordStats( $filter_matched );
return $filter_matched;
}
/** Returns an array [ list of actions taken by filter, error message to display, if any ] */
public static function executeFilterActions( $filters, $title, $vars ) {
$dbr = wfGetDB( DB_SLAVE );
// Retrieve the consequences.
$res = $dbr->select( 'abuse_filter_action', '*', array( 'afa_filter' => $filters ), __METHOD__ );
$actionsByFilter = array_fill_keys( $filters, array() );
$actionsTaken = array_fill_keys( $filters, array() );
// Categorise consequences by filter.
while ( $row = $dbr->fetchObject( $res ) ) {
$actionsByFilter[$row->afa_filter][$row->afa_consequence] = array( 'action' => $row->afa_consequence, 'parameters' => explode( "\n", $row->afa_parameters ) );
}
wfLoadExtensionMessages( 'AbuseFilter' );
$messages = array();
foreach( $actionsByFilter as $filter => $actions ) {
// Special-case handling for warnings.
if ( !empty( $actions['throttle'] ) ) {
$parameters = $actions['throttle']['parameters'];
$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 );
}
unset( $actions['throttle'] );
if (!$hitThrottle) {
$actionsTaken[$filter][] = 'throttle';
continue;
}
}
if ( !empty( $actions['warn'] ) ) {
$parameters = $actions['warn']['parameters'];
$warnKey = 'abusefilter-warned-'.$title->getPrefixedText();
if (!isset($_SESSION[$warnKey]) || !$_SESSION[$warnKey]) {
$_SESSION[$warnKey] = true;
// Threaten them a little bit
$msg = ( !empty($parameters[0]) && strlen($parameters[0]) ) ? $parameters[0] : 'abusefilter-warning';
$messages[] = wfMsgNoTrans( $msg, self::$filters[$filter]->af_public_comments ) . "<br />\n";
$actionsTaken[$filter][] = 'warn';
continue; // Don't do anything else.
} else {
// We already warned them
$_SESSION[$warnKey] = false;
}
unset( $actions['warn'] );
}
// Do the rest of the actions
foreach( $actions as $action => $info ) {
$newMsg = self::takeConsequenceAction( $action, $info['parameters'], $title, $vars, self::$filters[$filter]->af_public_comments );
if ($newMsg)
$messages[] = $newMsg;
$actionsTaken[$filter][] = $action;
}
}
return array( $actionsTaken, implode( "\n", $messages ) );
}
public static function filterAction( $vars, $title ) {
global $wgUser,$wgMemc;
$dbr = wfGetDB( DB_SLAVE );
$filter_matched = self::checkAllFilters( $vars );
// Short-cut any remaining code if no filters were hit.
if ( count( array_filter( $filter_matched) ) == 0 ) {
return true;
}
list( $actions_taken, $error_msg ) = self::executeFilterActions( array_keys( array_filter( $filter_matched ) ), $title, $vars );
// Create a template
$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() );
self::addLogEntries( $actions_taken, $log_template, $vars['ACTION'] );
return $error_msg;
}
public static function addLogEntries( $actions_taken, $log_template, $action ) {
$dbw = wfGetDB( DB_MASTER );
$log_rows = array();
foreach( $actions_taken as $filter => $actions ) {
$thisLog = $log_template;
$thisLog['afl_filter'] = $filter;
$thisLog['afl_action'] = $action;
$thisLog['afl_actions'] = implode( ',', $actions );
// Don't log if we were only throttling.
if ($thisLog['afl_actions'] != 'throttle') {
$log_rows[] = $thisLog;
}
}
if (!count($log_rows)) {
return;
}
$dbw->insert( 'abuse_filter_log', $log_rows, __METHOD__ );
}
public static function takeConsequenceAction( $action, $parameters, $title, $vars, $rule_desc ) {
wfLoadExtensionMessages( 'AbuseFilter' );
$display = '';
switch ($action) {
case 'disallow':
if (strlen($parameters[0])) {
$display .= wfMsgNoTrans( $parameters[0], $rule_desc ) . "\n";
} else {
// Generic message.
$display .= wfMsgNoTrans( 'abusefilter-disallowed', $rule_desc ) ."<br />\n";
}
break;
case 'block':
global $wgUser;
$filterUser = AbuseFilter::getFilterUser();
// Create a block.
$block = new Block;
$block->mAddress = $wgUser->getName();
$block->mUser = $wgUser->getId();
$block->mBy = $filterUser->getId();
$block->mByName = $filterUser->getName();
$block->mReason = wfMsgForContent( 'abusefilter-blockreason', $rule_desc );
$block->mTimestamp = wfTimestampNow();
$block->mAnonOnly = 1;
$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 'rangeblock':
global $wgUser;
$filterUser = AbuseFilter::getFilterUser();
$range = IP::toHex( wfGetIP() );
$range = substr( $range, 0, 4 ) . '0000';
$range = long2ip( hexdec( $range ) );
$range .= "/16";
$range = Block::normaliseRange( $range );
// Create a block.
$block = new Block;
$block->mAddress = $range;
$block->mUser = 0;
$block->mBy = $filterUser->getId();
$block->mByName = $filterUser->getName();
$block->mReason = wfMsgForContent( 'abusefilter-blockreason', $rule_desc );
$block->mTimestamp = wfTimestampNow();
$block->mAnonOnly = 0;
$block->mCreateAccount = 1;
$block->mExpiry = Block::parseExpiryInput( '1 week' );
$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, $range ),
wfMsgForContent( 'abusefilter-blockreason', $rule_desc ), $logParams, self::getFilterUser() );
$display .= wfMsgNoTrans( 'abusefilter-blocked-display', $rule_desc ) ."<br />\n";
break;
case 'degroup':
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()) {
$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;
// case 'tag':
// // Mark with a tag on recentchanges.
// global $wgUser;
//
// $actionID = implode( '-', array(
// $title->getPrefixedText(), $wgUser->getName(), $vars['ACTION']
// ) );
//
// AbuseFilter::$tagsToSet[$actionID] = $parameters;
// break;
}
return $display;
}
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) {
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;
$blocking_filters = array_keys( array_filter( $filters ) );
// Figure out if we've triggered overflows and blocks.
$overflow_triggered = (self::$condCount > $wgAbuseFilterConditionLimit);
$filter_triggered = count( $blocking_filters ) > 0;
// Store some keys...
$overflow_key = self::filterLimitReachedKey();
$total_key = self::filterUsedKey();
$total = $wgMemc->get( $total_key );
$storage_period = self::$statsStoragePeriod;
if (!$total || $total > 1000) {
// This is for if the total doesn't exist, or has gone past 1000.
// Recreate all the keys at the same time, so they expire together.
$wgMemc->set( $total_key, 0, $storage_period );
$wgMemc->set( $overflow_key, 0, $storage_period );
foreach( $filters as $filter => $matched ) {
$wgMemc->set( self::filterMatchesKey( $filter ), 0, $storage_period );
}
$wgMemc->set( self::filterMatchesKey(), 0, $storage_period );
return;
}
// Increment total
$wgMemc->incr( $total_key );
// Increment overflow counter, if our condition limit overflowed
if ($overflow_triggered) {
$wgMemc->incr( $overflow_key );
}
self::checkEmergencyDisable( $filters );
// Increment trigger counter
if ($filter_triggered) {
$wgMemc->incr( self::filterMatchesKey() );
}
$dbw = wfGetDB( DB_MASTER );
// Update hit-counter.
$dbw->update( 'abuse_filter', array( 'af_hit_count=af_hit_count+1' ), array( 'af_id' => array_keys( array_filter( $filters ) ) ), __METHOD__ );
}
public static function checkEmergencyDisable( $filters ) {
global $wgAbuseFilterEmergencyDisableThreshold, $wgAbuseFilterEmergencyDisableCount, $wgAbuseFilterEmergencyDisableAge, $wgMemc;
foreach( $filters as $filter => $matched ) {
if ($matched) {
// Increment counter
$matchCount = $wgMemc->get( self::filterMatchesKey( $filter ) );
// Handle missing keys...
if (!$matchCount) {
$wgMemc->set( self::filterMatchesKey( $filter ), 1, self::$statsStoragePeriod );
} else {
$wgMemc->incr( self::filterMatchesKey( $filter ) );
}
$matchCount++;
// Figure out if the filter is subject to being deleted.
$filter_age = wfTimestamp( TS_UNIX, self::$filters[$filter]->af_timestamp );
$throttle_exempt_time = $filter_age + $wgAbuseFilterEmergencyDisableAge;
if ($throttle_exempt_time > time() && $matchCount > $wgAbuseFilterEmergencyDisableCount && ($matchCount / $total) > $wgAbuseFilterEmergencyDisableThreshold) {
// More than $wgAbuseFilterEmergencyDisableCount matches, constituting more than $wgAbuseFilterEmergencyDisableThreshold (a fraction) of last few edits. Disable it.
$dbw = wfGetDB( DB_MASTER );
$dbw->update( 'abuse_filter', array( 'af_enabled' => 0, 'af_throttled' => 1 ), array( 'af_id' => $filter ), __METHOD__ );
}
}
}
}
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;
}
static function buildEditBox( $rules, $textName = 'wpFilterRules' ) {
global $wgOut;
$rules = Xml::textarea( $textName, ( isset( $rules ) ? $rules."\n" : "\n" ) );
$dropDown = array(
'op-arithmetic' => array('+' => 'addition', '-' => 'subtraction', '*' => 'multiplication', '/' => 'divide', '%' => 'modulo', '**' => 'pow'),
'op-comparison' => array('==' => 'equal', '!=' => 'notequal', '<' => 'lt', '>' => 'gt', '<=' => 'lte', '>=' => 'gte'),
'op-bool' => array( '!' => 'not', '&' => 'and', '|' => 'or', '^' => 'xor' ),
'misc' => array( 'in' => 'in', 'like' => 'like', '""' => 'stringlit', ),
'funcs' => array( 'length(string)' => 'length', 'lcase(string)' => 'lcase', 'ccnorm(string)' => 'ccnorm', 'rmdoubles(string)' => 'rmdoubles', 'specialratio(string)' => 'specialratio', 'norm(string)' => 'norm', 'count(needle,haystack)' => 'count' ),
'vars' => array( 'ACCOUNTNAME' => 'accountname', 'ACTION' => 'action', 'ADDED_LINES' => 'addedlines', 'EDIT_DELTA' => 'delta', 'EDIT_DIFF' => 'diff', 'NEW_SIZE' => 'newsize', 'OLD_SIZE' => 'oldsize', 'REMOVED_LINES' => 'removedlines', 'SUMMARY' => 'summary', 'ARTICLE_ARTICLEID' => 'article-id', 'ARTICLE_NAMESPACE' => 'article-ns', 'ARTICLE_TEXT' => 'article-text', 'ARTICLE_PREFIXEDTEXT' => 'article-prefixedtext', 'MOVED_FROM_ARTICLEID' => 'movedfrom-id', 'MOVED_FROM_NAMESPACE' => 'movedfrom-ns', 'MOVED_FROM_TEXT' => 'movedfrom-text', 'MOVED_FROM_PREFIXEDTEXT' => 'movedfrom-prefixedtext', 'MOVED_TO_ARTICLEID' => 'movedto-id', 'MOVED_TO_NAMESPACE' => 'movedto-ns', 'MOVED_TO_TEXT' => 'movedto-text', 'MOVED_TO_PREFIXEDTEXT' => 'movedto-prefixedtext', 'USER_EDITCOUNT' => 'user-editcount', 'USER_AGE' => 'user-age', 'USER_NAME' => 'user-name', 'USER_GROUPS' => 'user-groups', 'USER_EMAILCONFIRM' => 'user-emailconfirm'),
);
// Generate builder drop-down
$builder = '';
$builder .= Xml::option( wfMsg( "abusefilter-edit-builder-select") );
foreach( $dropDown as $group => $values ) {
$builder .= Xml::openElement( 'optgroup', array( 'label' => wfMsg( "abusefilter-edit-builder-group-$group" ) ) ) . "\n";
foreach( $values as $content => $name ) {
$builder .= Xml::option( wfMsg( "abusefilter-edit-builder-$group-$name" ), $content ) . "\n";
}
$builder .= Xml::closeElement( 'optgroup' ) . "\n";
}
$rules .= Xml::tags( 'select', array( 'id' => 'wpFilterBuilder', 'onchange' => 'addText();' ), $builder );
// Add syntax checking
$rules .= Xml::element( 'input', array( 'type' => 'button', 'onclick' => 'doSyntaxCheck()', 'value' => wfMsg( 'abusefilter-edit-check' ), 'id' => 'mw-abusefilter-syntaxcheck' ) );
$rules .= Xml::element( 'div', array( 'id' => 'mw-abusefilter-syntaxresult', 'style' => 'display: none;' ), '&nbsp;' );
// Add script
$editScript = file_get_contents(dirname(__FILE__)."/edit.js");
$editScript = "var wgFilterBoxName = ".Xml::encodeJSVar( $textName ).";\n$editScript";
$wgOut->addInlineScript( $editScript );
return $rules;
}
}