dbus: revamp fd passing for i/o restrictions

dbus/message_unittest.cc

 // Copyright (c) 2012 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 "dbus/message.h"
 
 #include "base/basictypes.h"
 #include "base/eintr_wrapper.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 89 matching lines @@
   if (!dbus::kDBusTypeUnixFdIsSupported) {
     LOG(WARNING) << "FD passing is not supported";
     return;
   }
 
   scoped_ptr<dbus::Response> message(dbus::Response::CreateEmpty());
   dbus::MessageWriter writer(message.get());
 
   // Append stdout.
   dbus::FileDescriptor temp(1);
+  // Descriptor should not be valid until checked.
+  ASSERT_FALSE(temp.is_valid());
+  // NB: thread IO requirements not relevant for unit tests.
+  temp.CheckValidity();
+  ASSERT_TRUE(temp.is_valid());
   writer.AppendFileDescriptor(temp);
 
   dbus::FileDescriptor fd_value;
 
   dbus::MessageReader reader(message.get());
   ASSERT_TRUE(reader.HasMoreData());
   ASSERT_TRUE(reader.PopFileDescriptor(&fd_value));
   ASSERT_FALSE(reader.HasMoreData());
+  // Descriptor is not valid until explicitly checked.
+  ASSERT_FALSE(fd_value.is_valid());
+  fd_value.CheckValidity();
+  ASSERT_TRUE(fd_value.is_valid());
 
   // Stdout should be returned but we cannot check the descriptor
   // value because stdout will be dup'd.  Instead check st_rdev
   // which should be identical.
   struct stat sb_stdout;
   int status_stdout = HANDLE_EINTR(fstat(1, &sb_stdout));
   ASSERT_TRUE(status_stdout >= 0);
   struct stat sb_fd;
   int status_fd = HANDLE_EINTR(fstat(fd_value.value(), &sb_fd));
   ASSERT_TRUE(status_fd >= 0);
@@ skipping 439 matching lines @@
 
   EXPECT_EQ("org.chromium.destination", message->GetDestination());
   EXPECT_EQ(dbus::ObjectPath("/org/chromium/path"), message->GetPath());
   EXPECT_EQ("org.chromium.interface", message->GetInterface());
   EXPECT_EQ("member", message->GetMember());
   EXPECT_EQ("org.chromium.error", message->GetErrorName());
   EXPECT_EQ(":1.2", message->GetSender());
   EXPECT_EQ(123U, message->GetSerial());
   EXPECT_EQ(456U, message->GetReplySerial());
 }