Limit Mojo messages recursion depth

mojo/public/cpp/bindings/lib/validation_util.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_UTIL_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_UTIL_H_
 
 #include <stdint.h>
 
 #include "mojo/public/cpp/bindings/lib/bindings_internal.h"
@@ skipping 114 matching lines @@
     ValidationContext* validation_context);
 bool ValidateHandleOrInterfaceNonNullable(
     const Handle_Data& input,
     const char* error_message,
     ValidationContext* validation_context);
 
 template <typename T>
 bool ValidateContainer(const Pointer<T>& input,
                        ValidationContext* validation_context,
                        const ContainerValidateParams* validate_params) {
+  ValidationContext::ScopedDepthTracker depth_tracker(validation_context);
+  if (validation_context->ExceedsMaxDepth()) {
+    ReportValidationError(validation_context,
+                          VALIDATION_ERROR_MAX_RECURSION_DEPTH);
+    return false;
+  }
   return ValidatePointer(input, validation_context) &&
          T::Validate(input.Get(), validation_context, validate_params);
 }
 
 template <typename T>
 bool ValidateStruct(const Pointer<T>& input,
                     ValidationContext* validation_context) {
+  ValidationContext::ScopedDepthTracker depth_tracker(validation_context);
+  if (validation_context->ExceedsMaxDepth()) {
+    ReportValidationError(validation_context,
+                          VALIDATION_ERROR_MAX_RECURSION_DEPTH);
+    return false;
+  }
   return ValidatePointer(input, validation_context) &&
          T::Validate(input.Get(), validation_context);
 }
 
 template <typename T>
 bool ValidateInlinedUnion(const T& input,
                           ValidationContext* validation_context) {
+  ValidationContext::ScopedDepthTracker depth_tracker(validation_context);
+  if (validation_context->ExceedsMaxDepth()) {
+    ReportValidationError(validation_context,
+                          VALIDATION_ERROR_MAX_RECURSION_DEPTH);
+    return false;
+  }
   return T::Validate(&input, validation_context, true);
 }
 
 template <typename T>
 bool ValidateNonInlinedUnion(const Pointer<T>& input,
                              ValidationContext* validation_context) {
+  ValidationContext::ScopedDepthTracker depth_tracker(validation_context);
+  if (validation_context->ExceedsMaxDepth()) {
+    ReportValidationError(validation_context,
+                          VALIDATION_ERROR_MAX_RECURSION_DEPTH);
+    return false;
+  }
   return ValidatePointer(input, validation_context) &&
          T::Validate(input.Get(), validation_context, false);
 }
 
 bool ValidateHandleOrInterface(const AssociatedInterface_Data& input,
                                ValidationContext* validation_context);
 bool ValidateHandleOrInterface(const AssociatedInterfaceRequest_Data& input,
                                ValidationContext* validation_context);
 bool ValidateHandleOrInterface(const Interface_Data& input,
                                ValidationContext* validation_context);
 bool ValidateHandleOrInterface(const Handle_Data& input,
                                ValidationContext* validation_context);
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_VALIDATION_UTIL_H_