mediawiki-extensions-AbuseF.../AbuseFilter.class.php

497 lines
14 KiB
PHP

<?php
if ( ! defined( 'MEDIAWIKI' ) )
die();
class AbuseFilter {
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 generateTitleVars( $title, $prefix ) {
$vars = array();
$vars[$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 );
}
}
return $vars;
}
public static function checkConditions( $conds, $vars ) {
$modifierWords = array( 'norm', 'supernorm', 'lcase', 'length' );
$operatorWords = array( 'eq', 'neq', 'gt', 'lt', 'regex' );
$validJoinConditions = array( '!', '|', '&' );
// Remove leading/trailing spaces
$conds = trim($conds);
// Is it a set?
if (substr( $conds, 0, 1 ) == '(' && substr( $conds, -1, 1 ) == ')' ) {
// We should have a set here.
$setInternal = substr($conds,1,-1);
// Get the join condition ( &, | or ! )
list($setJoinCondition,$conditionList) = explode(':', $setInternal, 2 );
$setJoinCondition = trim($setJoinCondition);
if (!in_array( $setJoinCondition, $validJoinConditions )) {
// Bad join condition
return false;
}
// Tokenise.
$allConditions = self::tokeniseList( $conditionList );
foreach( $allConditions as $thisCond ) {
if (trim($thisCond)=='') {
// Ignore it
$result = true;
} else {
$result = self::checkConditions( $thisCond, $vars );
}
// Need we short-circuit?
if ($setJoinCondition == '|' && $result) {
// Definite yes.
return true;
} elseif ($setJoinCondition == '&' && !$result) {
// Definite no.
return false;
} elseif ($setJoinCondition == '!' && $result) {
// Definite no.
return false;
}
}
// Return the default result.
return ($setJoinCondition != '|'); // Only OR returns false after checking all conditions.
}
// Grab the first word.
list ($thisWord) = explode( ' ', $conds );
$wordNum = 0;
// Check for modifiers
$modifier = '';
if (in_array( $thisWord, $modifierWords ) ) {
$modifier = $thisWord;
$wordNum++;
$thisWord = explode( ' ', $conds );
$thisWord = $thisWord[$wordNum];
}
if ( in_array( $thisWord, array_keys($vars ) ) ) {
$value = $vars[$thisWord];
if ($modifier) {
$value = self::modifyValue( $modifier, $value );
}
// We have a variable. Now read the next word to see what we're doing with it.
$wordNum++;
$thisWord = explode( ' ', $conds );
$thisWord = $thisWord[$wordNum];
if ( in_array( $thisWord, $operatorWords ) ) {
// Get the rest of the string after the operator.
$parameters = explode( ' ', $conds, $wordNum+2);
$parameters = $parameters[$wordNum+1];
return self::checkOperator( $thisWord, $value, $parameters );
}
} else {
print "Word $thisWord is not a variable (".implode(',', array_keys($vars)).")\n";
}
}
public static function tokeniseList( $list ) {
// Parse it, character by character.
$escapeNext = false;
$listLevel = 0;
$thisToken = '';
$allTokens = array();
for( $i=0;$i<strlen($list);$i++ ) {
$char = substr( $list, $i, 1 );
$suppressAdd = false;
// We don't care about semicolons and so on unless it's
if ($listLevel == 0) {
if ($char == "\\") {
if ($escapeNext) { // Escaped backslash
$escapeNext = false;
} else {
$escapeNext = true;
$suppressAdd = true;
}
} elseif ($char == ';') {
if ($escapeNext) {
$escapeNext = false; // Escaped semicolon
} else { // Next token, plz
$escapeNext = false;
$allTokens[] = $thisToken;
$thisToken = '';
$suppressAdd = true;
}
} elseif ($escapeNext) {
$escapeNext = false;
$thisToken .= "\\"; // The backslash wasn't intended to escape.
}
}
if ($char == '(' && $lastChar == ';') {
// A list!
$listLevel++;
} elseif ($char == ')' && ($lastChar == ';' || $lastChar == ')' || $lastChar = '') ) {
$listLevel--; // End of a list.
}
if (!$suppressAdd) {
$thisToken .= $char;
}
// Ignore whitespace.
if ($char != ' ') {
$lastChar = $char;
}
}
// Put any leftovers in
$allTokens[] = $thisToken;
return $allTokens;
}
public static function modifyValue( $modifier, $value ) {
if ($modifier == 'norm') {
return self::normalise( $value );
} elseif ($modifier == 'supernorm') {
return self::superNormalise( $value );
} elseif ($modifier == 'lcase') {
return strtolower($value);
} elseif ($modifier == 'length') {
return strlen($value);
} elseif ($modifier == 'specialratio') {
$specialsonly = preg_replace('/\w/', '', $value );
return (strlen($specialsonly) / strlen($value));
}
}
public static function checkOperator( $operator, $value, $parameters ) {
if ($operator == 'eq') {
return $value == $parameters;
} elseif ($operator == 'neq') {
return $value != $parameters;
} elseif ($operator == 'gt') {
return $value > $parameters;
} elseif ($operator == 'lt') {
return $value < $parameters;
} elseif ($operator == 'regex') {
return preg_match( $parameters, $value );
} else {
return false;
}
}
public static function superNormalise( $text ) {
$text = self::normalise( $text );
$text = preg_split( '//', $text, -1, PREG_SPLIT_NO_EMPTY ); // Split to a char array.
sort($text);
$text = array_unique( $text ); // Remove duplicate characters.
$text = implode( '', $text );
return $text;
}
public static function normalise( $text ) {
$old_text = $text;
$text = preg_replace( '/\W/', '', $text ); // Remove any special characters.
$text = strtolower($text);
$text = preg_split( '//', $text, -1, PREG_SPLIT_NO_EMPTY ); // Split to a char array.
$text = AntiSpoof::equivString( $text ); // Normalise
// Remove repeated characters, but not all duplicates.
$oldText = $text;
$text = array($oldText[0]);
for ($i=1;$i<count($oldText);$i++) {
if ($oldText[$i] != $oldText[$i-1]) {
$text[] = $oldText[$i];
}
}
$text = implode('', $text ); // Sort in alphabetical order, put back as it was.
return $text;
}
public static function filterAction( $vars, $title ) {
global $wgUser;
// 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();
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();
}
}
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')) desc" ) );
// We want throttles, warnings first, as they have a bit of a special treatment.
$actions_done = array();
$throttled_filters = array();
$display = '';
while ( $row = $dbr->fetchObject( $res ) ) {
$action_key = md5( $row->afa_consequence . $row->afa_parameters );
if (!in_array( $action_key, $actions_done ) && !in_array( $row->afa_filter, $throttled_filters ) ) {
$parameters = explode( "\n", $row->afa_parameters );
$result = self::takeConsequenceAction( $row->afa_consequence, $parameters, $title, $vars, &$display, &$continue );
$doneActionsByFilter[$row->afa_filter][] = $row->afa_consequence;
if (!$result) {
$throttled_filters[] = $row->afa_filter; // Only execute other actions for a filter if that filter's rate limiter has been tripped.
}
$actions_done[] = $action_key;
} 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, &$continue ) {
switch ($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( 'wfMsg', $parameters ) . "\n";
} else {
// Generic message.
$display .= wfMsg( 'abusefilter-warning' );
}
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( 'wfMsg', $parameters ) . "\n";
} else {
// Generic message.
$display .= wfMsg( 'abusefilter-disallowed' );
}
break;
case 'block':
wfLoadExtensionMessages( 'AbuseFilter' );
global $wgUser;
// Create a block.
$block = new Block;
$block->mAddress = $wgUser->getName();
$block->mUser = $wgUser->getId();
$block->mByName = wfMsgForContent( 'abusefilter-blocker' );
$block->mReason = wfMsgForContent( 'abusefilter-blockreason' );
$block->mTimestamp = wfTimestampNow();
$block->mEnableAutoblock = 1;
$block->mAngryAutoblock = 1; // Block lots of IPs
$block->mCreateAccount = 1;
$block->mExpiry = 'infinity';
$block->insert();
$display .= wfMsg( 'abusefilter-blocked-display' );
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;
// Remove all groups from the user. Ouch.
$groups = $wgUser->getGroups();
foreach( $groups as $group ) {
$wgUser->removeGroup( $group );
}
$display = wfMsg( 'abusefilter-degrouped' );
break;
case 'blockautopromote':
wfLoadExtensionMessages( 'AbuseFilter' );
global $wgUser, $wgMemc;
$blockPeriod = (int)mt_rand( 3*86400, 7*86400 ); // Block for 3-7 days.
$wgMemc->set( self::autoPromoteBlockKey( $wgUser ), true, $blockPeriod );
$display = wfMsg( 'abusefilter-autopromote-blocked' );
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() );
}
}