fix(graphql): filter schema metadata requests

api/src/unraid-api/graph/introspection-plugin.ts

@@ -1,41 +1,136 @@
 import type { ApolloServerPlugin, GraphQLRequestListener } from '@apollo/server';
+import type { DocumentNode, OperationDefinitionNode, SelectionSetNode } from 'graphql';
+import { Kind, parse } from 'graphql';
+
+const BLOCKED_INTROSPECTION_FIELDS = new Set(['__schema']);
+
+const hasBlockedIntrospectionField = (
+    selectionSet: SelectionSetNode,
+    fragments: Map<string, SelectionSetNode>,
+    visitedFragments = new Set<string>(),
+    atQueryRoot = true
+): boolean =>
+    selectionSet.selections.some((selection) => {
+        if (selection.kind === Kind.FIELD) {
+            return (
+                (atQueryRoot && BLOCKED_INTROSPECTION_FIELDS.has(selection.name.value)) ||
+                (selection.selectionSet !== undefined &&
+                    hasBlockedIntrospectionField(
+                        selection.selectionSet,
+                        fragments,
+                        visitedFragments,
+                        false
+                    ))
+            );
+        }
+
+        if (selection.kind === Kind.INLINE_FRAGMENT) {
+            return hasBlockedIntrospectionField(
+                selection.selectionSet,
+                fragments,
+                visitedFragments,
+                atQueryRoot
+            );
+        }
+
+        if (visitedFragments.has(selection.name.value)) {
+            return false;
+        }
+
+        const fragmentSelectionSet = fragments.get(selection.name.value);
+        if (!fragmentSelectionSet) {
+            return false;
+        }
+
+        visitedFragments.add(selection.name.value);
+        const blocked = hasBlockedIntrospectionField(
+            fragmentSelectionSet,
+            fragments,
+            visitedFragments,
+            atQueryRoot
+        );
+        visitedFragments.delete(selection.name.value);
+        return blocked;
+    });
+
+const isBlockedIntrospectionOperation = (
+    operation: OperationDefinitionNode,
+    document: DocumentNode
+): boolean => {
+    const fragments = new Map(
+        document.definitions
+            .filter((definition) => definition.kind === Kind.FRAGMENT_DEFINITION)
+            .map((definition) => [definition.name.value, definition.selectionSet])
+    );
+
+    return hasBlockedIntrospectionField(operation.selectionSet, fragments);
+};
+
+const getOperationFromDocument = (document: DocumentNode, operationName?: string) => {
+    const operations = document.definitions.filter(
+        (definition): definition is OperationDefinitionNode =>
+            definition.kind === Kind.OPERATION_DEFINITION
+    );
+
+    return (
+        operations.find((operation) => operation.name?.value === operationName) ??
+        (operations.length === 1 ? operations[0] : undefined)
+    );
+};
+
+const blockedIntrospectionBody = () => ({
+    kind: 'single' as const,
+    singleResult: {
+        errors: [
+            {
+                message:
+                    'GraphQL introspection is not allowed, but the current request is for introspection.',
+                extensions: {
+                    code: 'INTROSPECTION_DISABLED',
+                },
+            },
+        ],
+    },
+});
 
 export const createDynamicIntrospectionPlugin = (
     isSandboxEnabled: () => boolean
 ): ApolloServerPlugin => ({
     requestDidStart: async () =>
         ({
+            responseForOperation: async ({ document, operation, response }) => {
+                if (!isSandboxEnabled() && isBlockedIntrospectionOperation(operation, document)) {
+                    return {
+                        http: {
+                            status: 400,
+                            headers: response.http.headers,
+                        },
+                        body: blockedIntrospectionBody(),
+                    };
+                }
+
+                return null;
+            },
             willSendResponse: async (requestContext) => {
                 const { request, response } = requestContext;
 
-                // Detect introspection queries:
-                // 1. Standard operation name "IntrospectionQuery"
-                // 2. Queries containing __schema at root level (main introspection entry point)
-                // Note: __type and __typename are also used in regular queries, so we don't block them
-                const isIntrospectionRequest =
-                    request.operationName === 'IntrospectionQuery' ||
-                    (request.query &&
-                        // Check for __schema which is the main introspection entry point
-                        // Match patterns like: { __schema { ... } } or query { __schema { ... } }
-                        /\{\s*__schema\s*[{(]/.test(request.query));
-
-                if (isIntrospectionRequest && !isSandboxEnabled()) {
-                    response.body = {
-                        kind: 'single',
-                        singleResult: {
-                            errors: [
-                                {
-                                    message:
-                                        'GraphQL introspection is not allowed, but the current request is for introspection.',
-                                    extensions: {
-                                        code: 'INTROSPECTION_DISABLED',
-                                    },
-                                },
-                            ],
-                        },
-                    };
-                    if (response.http) {
-                        response.http.status = 400;
+                if (requestContext.operation || requestContext.document) {
+                    return;
+                }
+
+                if (!isSandboxEnabled() && request.query) {
+                    try {
+                        const document = parse(request.query);
+                        const operation = getOperationFromDocument(document, request.operationName);
+
+                        if (operation && isBlockedIntrospectionOperation(operation, document)) {
+                            response.body = blockedIntrospectionBody();
+                            if (response.http) {
+                                response.http.status = 400;
+                            }
+                        }
+                    } catch {
+                        return;
                     }
                 }
             },