mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/AbuseFilter.git
synced 2024-11-13 17:27:20 +00:00
e98799a00a
This allows sharing the code between cachingparser and the old parser (for DRY-ness), and even when the old parser will be killed, having the logic outside of the generic parse method seems saner. This copies what I446a307e5395ea8cc8ec5ca5d5390b074bea2f24 did for functions. Change-Id: Ie6290243a6c78661510a9b4cb713d6e7b2778248
394 lines
13 KiB
PHP
394 lines
13 KiB
PHP
<?php
|
|
/**
|
|
* AbuseFilterCachingParser is the version of AbuseFilterParser which parses
|
|
* the code into an abstract syntax tree before evaluating it, and caches that
|
|
* tree.
|
|
*
|
|
* It currently inherits AbuseFilterParser in order to avoid code duplication.
|
|
* In future, this code will replace current AbuseFilterParser entirely.
|
|
*
|
|
* @todo Override checkSyntax and make it only try to build the AST. That would mean faster results,
|
|
* and no need to mess with DUNDEFINED and the like. However, we must first try to reduce the
|
|
* amount of runtime-only exceptions, and try to detect them in the AFPTreeParser instead.
|
|
* Otherwise, people may be able to save a broken filter without the syntax check reporting that.
|
|
*/
|
|
class AbuseFilterCachingParser extends AbuseFilterParser {
|
|
const CACHE_VERSION = 1;
|
|
|
|
/**
|
|
* Return the generated version of the parser for cache invalidation
|
|
* purposes. Automatically tracks list of all functions and invalidates the
|
|
* cache if it is changed.
|
|
* @return string
|
|
*/
|
|
public static function getCacheVersion() {
|
|
static $version = null;
|
|
if ( $version !== null ) {
|
|
return $version;
|
|
}
|
|
|
|
$versionKey = [
|
|
self::CACHE_VERSION,
|
|
AFPTreeParser::CACHE_VERSION,
|
|
AbuseFilterTokenizer::CACHE_VERSION,
|
|
array_keys( AbuseFilterParser::$mFunctions ),
|
|
array_keys( AbuseFilterParser::$mKeywords ),
|
|
];
|
|
$version = hash( 'sha256', serialize( $versionKey ) );
|
|
|
|
return $version;
|
|
}
|
|
|
|
/**
|
|
* Resets the state of the parser
|
|
*/
|
|
public function resetState() {
|
|
$this->mVariables = new AbuseFilterVariableHolder;
|
|
$this->mCur = new AFPToken();
|
|
$this->mCondCount = 0;
|
|
$this->mAllowShort = true;
|
|
}
|
|
|
|
/**
|
|
* @param string $code
|
|
* @return AFPData
|
|
*/
|
|
public function intEval( $code ) : AFPData {
|
|
$startTime = microtime( true );
|
|
$tree = $this->getTree( $code );
|
|
|
|
$res = $this->evalTree( $tree );
|
|
|
|
if ( $res->getType() === AFPData::DUNDEFINED ) {
|
|
$res = new AFPData( AFPData::DBOOL, false );
|
|
}
|
|
$this->statsd->timing( 'abusefilter_cachingParser_full', microtime( true ) - $startTime );
|
|
return $res;
|
|
}
|
|
|
|
/**
|
|
* @param string $code
|
|
* @return AFPSyntaxTree
|
|
*/
|
|
private function getTree( $code ) : AFPSyntaxTree {
|
|
return $this->cache->getWithSetCallback(
|
|
$this->cache->makeGlobalKey(
|
|
__CLASS__,
|
|
self::getCacheVersion(),
|
|
hash( 'sha256', $code )
|
|
),
|
|
BagOStuff::TTL_DAY,
|
|
function () use ( $code ) {
|
|
$parser = new AFPTreeParser( $this->cache, $this->logger, $this->statsd );
|
|
$parser->setFilter( $this->mFilter );
|
|
return $parser->parse( $code );
|
|
}
|
|
);
|
|
}
|
|
|
|
/**
|
|
* @param AFPSyntaxTree $tree
|
|
* @return AFPData
|
|
*/
|
|
private function evalTree( AFPSyntaxTree $tree ) : AFPData {
|
|
$startTime = microtime( true );
|
|
$root = $tree->getRoot();
|
|
|
|
if ( !$root ) {
|
|
return new AFPData( AFPData::DNULL );
|
|
}
|
|
|
|
$ret = $this->evalNode( $root );
|
|
$this->statsd->timing( 'abusefilter_cachingParser_eval', microtime( true ) - $startTime );
|
|
return $ret;
|
|
}
|
|
|
|
/**
|
|
* Evaluate the value of the specified AST node.
|
|
*
|
|
* @param AFPTreeNode $node The node to evaluate.
|
|
* @return AFPData|AFPTreeNode|string
|
|
* @throws AFPException
|
|
* @throws AFPUserVisibleException
|
|
* @throws MWException
|
|
*/
|
|
private function evalNode( AFPTreeNode $node ) {
|
|
// A lot of AbuseFilterParser features rely on $this->mCur->pos or
|
|
// $this->mPos for error reporting.
|
|
// FIXME: this is a hack which needs to be removed when the parsers are merged.
|
|
$this->mPos = $node->position;
|
|
$this->mCur->pos = $node->position;
|
|
|
|
switch ( $node->type ) {
|
|
case AFPTreeNode::ATOM:
|
|
$tok = $node->children;
|
|
switch ( $tok->type ) {
|
|
case AFPToken::TID:
|
|
return $this->getVarValue( strtolower( $tok->value ) );
|
|
case AFPToken::TSTRING:
|
|
return new AFPData( AFPData::DSTRING, $tok->value );
|
|
case AFPToken::TFLOAT:
|
|
return new AFPData( AFPData::DFLOAT, $tok->value );
|
|
case AFPToken::TINT:
|
|
return new AFPData( AFPData::DINT, $tok->value );
|
|
/** @noinspection PhpMissingBreakStatementInspection */
|
|
case AFPToken::TKEYWORD:
|
|
switch ( $tok->value ) {
|
|
case "true":
|
|
return new AFPData( AFPData::DBOOL, true );
|
|
case "false":
|
|
return new AFPData( AFPData::DBOOL, false );
|
|
case "null":
|
|
return new AFPData( AFPData::DNULL );
|
|
}
|
|
// Fallthrough intended
|
|
default:
|
|
// @codeCoverageIgnoreStart
|
|
throw new AFPException( "Unknown token provided in the ATOM node" );
|
|
// @codeCoverageIgnoreEnd
|
|
}
|
|
case AFPTreeNode::ARRAY_DEFINITION:
|
|
$items = [];
|
|
// Foreach is usually faster than array_map
|
|
// @phan-suppress-next-line PhanTypeSuspiciousNonTraversableForeach children is array here
|
|
foreach ( $node->children as $el ) {
|
|
$items[] = $this->evalNode( $el );
|
|
}
|
|
return new AFPData( AFPData::DARRAY, $items );
|
|
|
|
case AFPTreeNode::FUNCTION_CALL:
|
|
$functionName = $node->children[0];
|
|
$args = array_slice( $node->children, 1 );
|
|
|
|
$dataArgs = [];
|
|
// Foreach is usually faster than array_map
|
|
foreach ( $args as $arg ) {
|
|
$dataArgs[] = $this->evalNode( $arg );
|
|
}
|
|
|
|
return $this->callFunc( $functionName, $dataArgs );
|
|
case AFPTreeNode::ARRAY_INDEX:
|
|
list( $array, $offset ) = $node->children;
|
|
|
|
$array = $this->evalNode( $array );
|
|
|
|
if ( $array->getType() === AFPData::DUNDEFINED ) {
|
|
return new AFPData( AFPData::DUNDEFINED );
|
|
}
|
|
|
|
if ( $array->getType() !== AFPData::DARRAY ) {
|
|
throw new AFPUserVisibleException( 'notarray', $node->position, [] );
|
|
}
|
|
|
|
$offset = $this->evalNode( $offset )->toInt();
|
|
|
|
$array = $array->toArray();
|
|
if ( count( $array ) <= $offset ) {
|
|
throw new AFPUserVisibleException( 'outofbounds', $node->position,
|
|
[ $offset, count( $array ) ] );
|
|
} elseif ( $offset < 0 ) {
|
|
throw new AFPUserVisibleException( 'negativeindex', $node->position, [ $offset ] );
|
|
}
|
|
|
|
return $array[$offset];
|
|
|
|
case AFPTreeNode::UNARY:
|
|
list( $operation, $argument ) = $node->children;
|
|
$argument = $this->evalNode( $argument );
|
|
if ( $operation === '-' ) {
|
|
return $argument->unaryMinus();
|
|
}
|
|
return $argument;
|
|
|
|
case AFPTreeNode::KEYWORD_OPERATOR:
|
|
list( $keyword, $leftOperand, $rightOperand ) = $node->children;
|
|
$leftOperand = $this->evalNode( $leftOperand );
|
|
$rightOperand = $this->evalNode( $rightOperand );
|
|
|
|
return $this->callKeyword( $keyword, $leftOperand, $rightOperand );
|
|
case AFPTreeNode::BOOL_INVERT:
|
|
list( $argument ) = $node->children;
|
|
$argument = $this->evalNode( $argument );
|
|
return $argument->boolInvert();
|
|
|
|
case AFPTreeNode::POW:
|
|
list( $base, $exponent ) = $node->children;
|
|
$base = $this->evalNode( $base );
|
|
$exponent = $this->evalNode( $exponent );
|
|
return $base->pow( $exponent );
|
|
|
|
case AFPTreeNode::MUL_REL:
|
|
list( $op, $leftOperand, $rightOperand ) = $node->children;
|
|
$leftOperand = $this->evalNode( $leftOperand );
|
|
$rightOperand = $this->evalNode( $rightOperand );
|
|
return $leftOperand->mulRel( $rightOperand, $op, $node->position );
|
|
|
|
case AFPTreeNode::SUM_REL:
|
|
list( $op, $leftOperand, $rightOperand ) = $node->children;
|
|
$leftOperand = $this->evalNode( $leftOperand );
|
|
$rightOperand = $this->evalNode( $rightOperand );
|
|
switch ( $op ) {
|
|
case '+':
|
|
return $leftOperand->sum( $rightOperand );
|
|
case '-':
|
|
return $leftOperand->sub( $rightOperand );
|
|
default:
|
|
// @codeCoverageIgnoreStart
|
|
throw new AFPException( "Unknown sum-related operator: {$op}" );
|
|
// @codeCoverageIgnoreEnd
|
|
}
|
|
|
|
case AFPTreeNode::COMPARE:
|
|
list( $op, $leftOperand, $rightOperand ) = $node->children;
|
|
$leftOperand = $this->evalNode( $leftOperand );
|
|
$rightOperand = $this->evalNode( $rightOperand );
|
|
$this->raiseCondCount();
|
|
return $leftOperand->compareOp( $rightOperand, $op );
|
|
|
|
case AFPTreeNode::LOGIC:
|
|
list( $op, $leftOperand, $rightOperand ) = $node->children;
|
|
$leftOperand = $this->evalNode( $leftOperand );
|
|
$value = $leftOperand->getType() === AFPData::DUNDEFINED ? false : $leftOperand->toBool();
|
|
// Short-circuit.
|
|
if ( ( !$value && $op === '&' ) || ( $value && $op === '|' ) ) {
|
|
if ( $rightOperand instanceof AFPTreeNode ) {
|
|
$this->maybeDiscardNode( $rightOperand );
|
|
}
|
|
return $leftOperand;
|
|
}
|
|
$rightOperand = $this->evalNode( $rightOperand );
|
|
return $leftOperand->boolOp( $rightOperand, $op );
|
|
|
|
case AFPTreeNode::CONDITIONAL:
|
|
list( $condition, $valueIfTrue, $valueIfFalse ) = $node->children;
|
|
$condition = $this->evalNode( $condition );
|
|
$isTrue = $condition->getType() === AFPData::DUNDEFINED ? false : $condition->toBool();
|
|
if ( $isTrue ) {
|
|
if ( $valueIfFalse !== null ) {
|
|
$this->maybeDiscardNode( $valueIfFalse );
|
|
}
|
|
return $this->evalNode( $valueIfTrue );
|
|
} else {
|
|
$this->maybeDiscardNode( $valueIfTrue );
|
|
return $valueIfFalse !== null
|
|
? $this->evalNode( $valueIfFalse )
|
|
// We assume null as default if the else is missing
|
|
: new AFPData( AFPData::DNULL );
|
|
}
|
|
|
|
case AFPTreeNode::ASSIGNMENT:
|
|
list( $varName, $value ) = $node->children;
|
|
$value = $this->evalNode( $value );
|
|
$this->setUserVariable( $varName, $value );
|
|
return $value;
|
|
|
|
case AFPTreeNode::INDEX_ASSIGNMENT:
|
|
list( $varName, $offset, $value ) = $node->children;
|
|
|
|
if ( $this->isBuiltinVar( $varName ) ) {
|
|
throw new AFPUserVisibleException( 'overridebuiltin', $node->position, [ $varName ] );
|
|
}
|
|
$array = $this->getVarValue( $varName );
|
|
|
|
$value = $this->evalNode( $value );
|
|
if ( $array->getType() !== AFPData::DUNDEFINED ) {
|
|
// If it's a DUNDEFINED, leave it as is
|
|
if ( $array->getType() !== AFPData::DARRAY ) {
|
|
throw new AFPUserVisibleException( 'notarray', $node->position, [] );
|
|
}
|
|
|
|
$offset = $this->evalNode( $offset )->toInt();
|
|
|
|
$array = $array->toArray();
|
|
if ( count( $array ) <= $offset ) {
|
|
throw new AFPUserVisibleException( 'outofbounds', $node->position,
|
|
[ $offset, count( $array ) ] );
|
|
} elseif ( $offset < 0 ) {
|
|
throw new AFPUserVisibleException( 'negativeindex', $node->position, [ $offset ] );
|
|
}
|
|
|
|
$array[$offset] = $value;
|
|
$this->setUserVariable( $varName, new AFPData( AFPData::DARRAY, $array ) );
|
|
}
|
|
|
|
return $value;
|
|
|
|
case AFPTreeNode::ARRAY_APPEND:
|
|
list( $varName, $value ) = $node->children;
|
|
|
|
if ( $this->isBuiltinVar( $varName ) ) {
|
|
throw new AFPUserVisibleException( 'overridebuiltin', $node->position, [ $varName ] );
|
|
}
|
|
|
|
$array = $this->getVarValue( $varName );
|
|
if ( $array->getType() !== AFPData::DUNDEFINED ) {
|
|
// If it's a DUNDEFINED, leave it as is
|
|
if ( $array->getType() !== AFPData::DARRAY ) {
|
|
throw new AFPUserVisibleException( 'notarray', $node->position, [] );
|
|
}
|
|
|
|
$array = $array->toArray();
|
|
$array[] = $this->evalNode( $value );
|
|
$this->setUserVariable( $varName, new AFPData( AFPData::DARRAY, $array ) );
|
|
}
|
|
return $value;
|
|
|
|
case AFPTreeNode::SEMICOLON:
|
|
$lastValue = null;
|
|
// @phan-suppress-next-line PhanTypeSuspiciousNonTraversableForeach children is array here
|
|
foreach ( $node->children as $statement ) {
|
|
$lastValue = $this->evalNode( $statement );
|
|
}
|
|
|
|
return $lastValue;
|
|
default:
|
|
// @codeCoverageIgnoreStart
|
|
throw new AFPException( "Unknown node type passed: {$node->type}" );
|
|
// @codeCoverageIgnoreEnd
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Given a node that we don't need to evaluate, decide what to do with it. The nodes passed in
|
|
* will usually be discarded by short-circuit evaluation. If we allow it, then we just hoist
|
|
* the variables assigned in any descendant of the node. Otherwise, we fully evaluate the node.
|
|
*
|
|
* @param AFPTreeNode $node
|
|
*/
|
|
private function maybeDiscardNode( AFPTreeNode $node ) {
|
|
if ( $this->mAllowShort ) {
|
|
$this->discardWithHoisting( $node );
|
|
} else {
|
|
$this->evalNode( $node );
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Intended to be used for short-circuit as a solution for T214674.
|
|
* Given a node, check it and its children; if there are assignments of non-existing variables,
|
|
* hoist them. In case of index assignment or array append, the old value is always erased and
|
|
* overwritten with a DUNDEFINED. This is used to allow stuff like:
|
|
* false & ( var := 'foo' ); var == 2
|
|
* or
|
|
* if ( false ) then ( var := 'foo' ) else ( 1 ) end; var == 2
|
|
* where `false` is something evaluated as false at runtime.
|
|
*
|
|
* @note This method doesn't check whether the variable exists in case of index assignments.
|
|
* Hence, in `false & (nonexistent[] := 2)`, `nonexistent` would be hoisted without errors.
|
|
* However, that would by caught by checkSyntax, so we can avoid checking here: we'd need
|
|
* way more context than we currently have.
|
|
*
|
|
* @param AFPTreeNode $node
|
|
*/
|
|
private function discardWithHoisting( AFPTreeNode $node ) {
|
|
foreach ( $node->getInnerAssignments() as $name ) {
|
|
if (
|
|
!$this->mVariables->varIsSet( $name ) ||
|
|
$this->mVariables->getVar( $name )->getType() === AFPData::DARRAY
|
|
) {
|
|
$this->setUserVariable( $name, new AFPData( AFPData::DUNDEFINED ) );
|
|
}
|
|
}
|
|
}
|
|
}
|