[mojo-edk] Sanity checks on ports message parsing

mojo/edk/system/ports/message.h

 // Copyright 2016 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_EDK_SYSTEM_PORTS_MESSAGE_H_
 #define MOJO_EDK_SYSTEM_PORTS_MESSAGE_H_
 
 #include <stddef.h>
 
 #include <memory>
 
 #include "mojo/edk/system/ports/name.h"
 
 namespace mojo {
 namespace edk {
 namespace ports {
 
 // A message consists of a header (array of bytes), payload (array of bytes)
 // and an array of ports. The header is used by the Node implementation.
 //
 // This class is designed to be subclassed, and the subclass is responsible for
 // providing the underlying storage. The header size will be aligned, and it
 // should be followed in memory by the array of ports and finally the payload.
 //
 // NOTE: This class does not manage the lifetime of the ports it references.
 class Message {
  public:
   virtual ~Message() {}
 
-  // Inspect the message at |bytes| and return the size of each section.
-  static void Parse(const void* bytes,
+  // Inspect the message at |bytes| and return the size of each section. Returns
+  // |false| if the message is malformed and |true| otherwise.
+  static bool Parse(const void* bytes,
                     size_t num_bytes,
                     size_t* num_header_bytes,
                     size_t* num_payload_bytes,
                     size_t* num_ports_bytes);
 
   void* mutable_header_bytes() { return start_; }
   const void* header_bytes() const { return start_; }
   size_t num_header_bytes() const { return num_header_bytes_; }
 
   void* mutable_payload_bytes() {
@@ skipping 41 matching lines @@
   size_t num_payload_bytes_ = 0;
 };
 
 using ScopedMessage = std::unique_ptr<Message>;
 
 }  // namespace ports
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_PORTS_MESSAGE_H_