Limit Mojo messages recursion depth

mojo/public/cpp/bindings/tests/validation_unittest.cc

 // Copyright 2014 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.
 
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <algorithm>
 #include <string>
 #include <utility>
@@ skipping 406 matching lines @@
 // This test is similar to the BoundsCheck test but for responses.
 TEST_F(ValidationTest, ResponseBoundsCheck) {
   DummyMessageReceiver dummy_receiver;
   mojo::FilterChain validators(&dummy_receiver);
   validators.Append<mojo::MessageHeaderValidator>();
   validators.Append<BoundsCheckTestInterface::ResponseValidator_>();
 
   RunValidationTests("resp_boundscheck_", &validators);
 }
 
+// Test that the client cannot send a message (e.g. a recursively defined
+// struct) so deep that the validation code blows the stack. The validation code
+// should check for this case and return a validation error.
+TEST_F(ValidationTest, RequestMaxRecursionDepth) {
+  DummyMessageReceiver dummy_receiver;
+  mojo::FilterChain validators(&dummy_receiver);
+  validators.Append<mojo::MessageHeaderValidator>();
+  validators.Append<ConformanceTestInterface::RequestValidator_>();
+
+  RunValidationTests("req_max_recursion_depth", &validators);

[yzshen1, 2016/09/07 16:51:20]

Does it make sense to use the same prefix as other conformance tests (So it will
be handled by line 383 above), and then change the validation tests of JS/Java
to skip this test case and add TODOs?

[tibell, 2016/09/08 00:03:38]

Done.

+}
+
 // Test that InterfacePtr<X> applies the correct validators and they don't
 // conflict with each other:
 //   - MessageHeaderValidator
 //   - X::ResponseValidator_
 TEST_F(ValidationIntegrationTest, InterfacePtr) {
   IntegrationTestInterfacePtr interface_ptr = MakeProxy(
       InterfacePtrInfo<IntegrationTestInterface>(testee_endpoint(), 0u));
   interface_ptr.internal_state()->EnableTestingMode();
 
   RunValidationTests("integration_intf_resp", test_message_receiver());
@@ skipping 53 matching lines @@
   EXPECT_TRUE(IsKnownEnumValue(static_cast<StructWithEnum::EnumWithin>(0)));
   EXPECT_TRUE(IsKnownEnumValue(static_cast<StructWithEnum::EnumWithin>(1)));
   EXPECT_TRUE(IsKnownEnumValue(static_cast<StructWithEnum::EnumWithin>(2)));
   EXPECT_TRUE(IsKnownEnumValue(static_cast<StructWithEnum::EnumWithin>(3)));
   EXPECT_FALSE(IsKnownEnumValue(static_cast<StructWithEnum::EnumWithin>(4)));
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo