Version 4.5.0

system/3rd_party/graphql-php/Validator/Rules/QueryDepth.php

@@ -0,0 +1,119 @@
+<?php
+namespace GraphQL\Validator\Rules;
+
+use GraphQL\Error\Error;
+use GraphQL\Language\AST\FieldNode;
+use GraphQL\Language\AST\FragmentSpreadNode;
+use GraphQL\Language\AST\InlineFragmentNode;
+use GraphQL\Language\AST\Node;
+use GraphQL\Language\AST\NodeKind;
+use GraphQL\Language\AST\OperationDefinitionNode;
+use GraphQL\Language\AST\SelectionSetNode;
+use GraphQL\Validator\ValidationContext;
+
+class QueryDepth extends AbstractQuerySecurity
+{
+    /**
+     * @var int
+     */
+    private $maxQueryDepth;
+
+    public function __construct($maxQueryDepth)
+    {
+        $this->setMaxQueryDepth($maxQueryDepth);
+    }
+
+    /**
+     * Set max query depth. If equal to 0 no check is done. Must be greater or equal to 0.
+     *
+     * @param $maxQueryDepth
+     */
+    public function setMaxQueryDepth($maxQueryDepth)
+    {
+        $this->checkIfGreaterOrEqualToZero('maxQueryDepth', $maxQueryDepth);
+
+        $this->maxQueryDepth = (int) $maxQueryDepth;
+    }
+
+    public function getMaxQueryDepth()
+    {
+        return $this->maxQueryDepth;
+    }
+
+    public static function maxQueryDepthErrorMessage($max, $count)
+    {
+        return sprintf('Max query depth should be %d but got %d.', $max, $count);
+    }
+
+    public function getVisitor(ValidationContext $context)
+    {
+        return $this->invokeIfNeeded(
+            $context,
+            [
+                NodeKind::OPERATION_DEFINITION => [
+                    'leave' => function (OperationDefinitionNode $operationDefinition) use ($context) {
+                        $maxDepth = $this->fieldDepth($operationDefinition);
+
+                        if ($maxDepth > $this->getMaxQueryDepth()) {
+                            $context->reportError(
+                                new Error($this->maxQueryDepthErrorMessage($this->getMaxQueryDepth(), $maxDepth))
+                            );
+                        }
+                    },
+                ],
+            ]
+        );
+    }
+
+    protected function isEnabled()
+    {
+        return $this->getMaxQueryDepth() !== static::DISABLED;
+    }
+
+    private function fieldDepth($node, $depth = 0, $maxDepth = 0)
+    {
+        if (isset($node->selectionSet) && $node->selectionSet instanceof SelectionSetNode) {
+            foreach ($node->selectionSet->selections as $childNode) {
+                $maxDepth = $this->nodeDepth($childNode, $depth, $maxDepth);
+            }
+        }
+
+        return $maxDepth;
+    }
+
+    private function nodeDepth(Node $node, $depth = 0, $maxDepth = 0)
+    {
+        switch ($node->kind) {
+            case NodeKind::FIELD:
+                /* @var FieldNode $node */
+                // node has children?
+                if (null !== $node->selectionSet) {
+                    // update maxDepth if needed
+                    if ($depth > $maxDepth) {
+                        $maxDepth = $depth;
+                    }
+                    $maxDepth = $this->fieldDepth($node, $depth + 1, $maxDepth);
+                }
+                break;
+
+            case NodeKind::INLINE_FRAGMENT:
+                /* @var InlineFragmentNode $node */
+                // node has children?
+                if (null !== $node->selectionSet) {
+                    $maxDepth = $this->fieldDepth($node, $depth, $maxDepth);
+                }
+                break;
+
+            case NodeKind::FRAGMENT_SPREAD:
+                /* @var FragmentSpreadNode $node */
+                $fragment = $this->getFragment($node);
+
+                if (null !== $fragment) {
+                    $maxDepth = $this->fieldDepth($fragment, $depth, $maxDepth);
+                }
+                break;
+        }
+
+        return $maxDepth;
+    }
+}