Add rights for mapping buffer. Update (shared) buffer APIs.

mojo/edk/system/core.cc

 // Copyright 2013 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 "mojo/edk/system/core.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 620 matching lines @@
 
   new_buffer_handle.Put(new_handle);
   return MOJO_RESULT_OK;
 }
 
 MojoResult Core::GetBufferInformation(MojoHandle buffer_handle,
                                       UserPointer<MojoBufferInformation> info,
                                       uint32_t info_num_bytes) {
   RefPtr<Dispatcher> dispatcher;
   MojoResult result =
-      GetDispatcherAndCheckRights(buffer_handle, MOJO_HANDLE_RIGHT_READ,
+      GetDispatcherAndCheckRights(buffer_handle, MOJO_HANDLE_RIGHT_GET_OPTIONS,
                                   EntrypointClass::BUFFER, &dispatcher);
   if (result != MOJO_RESULT_OK)
     return result;
 
   return dispatcher->GetBufferInformation(info, info_num_bytes);
 }
 
 MojoResult Core::MapBuffer(MojoHandle buffer_handle,
                            uint64_t offset,
                            uint64_t num_bytes,
                            UserPointer<void*> buffer,
                            MojoMapBufferFlags flags) {
   RefPtr<Dispatcher> dispatcher;
-  // TODO(vtl): Is this right? Or should there be a "map" right? Probably I need
-  // to rethink rights for buffers.
-  MojoResult result =
-      GetDispatcherAndCheckRights(buffer_handle, MOJO_HANDLE_RIGHT_WRITE,
-                                  EntrypointClass::BUFFER, &dispatcher);
+  // TODO(vtl): Currently we can only map read/write. So both
+  // |MOJO_HANDLE_RIGHT_MAP_READABLE| and |MOJO_HANDLE_RIGHT_MAP_WRITABLE| are
+  // required.
+  MojoResult result = GetDispatcherAndCheckRights(
+      buffer_handle,
+      MOJO_HANDLE_RIGHT_MAP_READABLE | MOJO_HANDLE_RIGHT_MAP_WRITABLE,
+      EntrypointClass::BUFFER, &dispatcher);
   if (result != MOJO_RESULT_OK)
     return result;
 
   std::unique_ptr<PlatformSharedBufferMapping> mapping;
   result = dispatcher->MapBuffer(offset, num_bytes, flags, &mapping);
   if (result != MOJO_RESULT_OK)
     return result;
 
   DCHECK(mapping);
   void* address = mapping->GetBase();
@@ skipping 78 matching lines @@
   if (signals_states) {
     for (; i < num_handles; i++)
       signals_states[i] = dispatchers[i]->GetHandleSignalsState();
   }
 
   return result;
 }
 
 }  // namespace system
 }  // namespace mojo