Mojo cpp bindings: add support for validating incoming messages.

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

 // 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_ROUTER_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_ROUTER_H_
 
 #include <map>
 
 #include "mojo/public/cpp/bindings/lib/connector.h"
 #include "mojo/public/cpp/bindings/lib/shared_data.h"
+#include "mojo/public/cpp/bindings/lib/validator_chain.h"
 
 namespace mojo {
 namespace internal {
 
 class Router : public MessageReceiver {
  public:
-  // The Router takes ownership of |message_pipe|.
-  explicit Router(ScopedMessagePipeHandle message_pipe,
-                  MojoAsyncWaiter* waiter = GetDefaultAsyncWaiter());
+  Router(ScopedMessagePipeHandle message_pipe,
+         ValidatorChain validators,

[darin (slow to review), 2014/05/12 17:28:26]

hmm, instead of passing the validator chain to Router, couldn't we just put all
of the validators being the incoming receiver?

[yzshen1, 2014/05/12 21:59:58]

We not only need to validate messages received by |incoming_receiver_|, but also
need to validate those response messages processed by Router to trigger
responders.

+         MojoAsyncWaiter* waiter = GetDefaultAsyncWaiter());
   virtual ~Router();
 
   // Sets the receiver to handle messages read from the message pipe that do
   // not have the kMessageIsResponse flag set.
   void set_incoming_receiver(MessageReceiver* receiver) {
     incoming_receiver_ = receiver;
   }
 
   // Sets the error handler to receive notifications when an error is
   // encountered while reading from the pipe or waiting to read from the pipe.
@@ skipping 36 matching lines @@
     // MessageReceiver implementation:
     virtual bool Accept(Message* message) MOJO_OVERRIDE;
     virtual bool AcceptWithResponder(Message* message,
                                      MessageReceiver* responder) MOJO_OVERRIDE;
    private:
     Router* router_;
   };
 
   bool HandleIncomingMessage(Message* message);
 
+  HandleIncomingMessageThunk thunk_;
+  ValidatorChain validators_;
   Connector connector_;
   SharedData<Router*> weak_self_;
   MessageReceiver* incoming_receiver_;
-  HandleIncomingMessageThunk thunk_;
   ResponderMap responders_;
   uint64_t next_request_id_;
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_ROUTER_H_