Framework to allow Chromoting host to respect NAT traversal policy in linux.

remoting/host/plugin/policy_hack/nat_policy_linux.h

+// Copyright (c) 2011 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.
+

[dmac, 2011/08/10 21:39:00]

why do we have a header for this as opposed to putting it directly in the .cc
file? That would match the rest of our creation patterns.

Same for the mac and win versions.

[awong, 2011/08/11 01:23:29]

hmm...good point. collapsed.

+#ifndef REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_LINUX_H_
+#define REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_LINUX_H_
+
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/memory/weak_ptr.h"
+#include "base/scoped_ptr.h"
+#include "base/time.h"
+#include "base/values.h"
+#include "remoting/host/plugin/policy_hack/nat_policy.h"
+
+namespace base {
+
+class MessageLoopProxy;
+class WaitableEvent;
+
+namespace files {
+class FilePathWatcher;
+}  // namespace base
+
+}  // namespace files
+
+namespace remoting {
+namespace policy_hack {
+
+class NatPolicyLinux : public NatPolicy {
+ public:
+  NatPolicyLinux(const FilePath& config_dir,
+                 const NatPolicy::NatEnabledCallback& nat_enabled_cb);
+  ~NatPolicyLinux();

[dmac, 2011/08/10 21:39:00]

I know you get this virtual by default (having inherited from a virtual) but is
it worth marking it virtual here just to make sure other people don't freak?

[awong, 2011/08/11 01:23:29]

Yes. Good catch. Fixed.

+
+  virtual void StartWatching() OVERRIDE;
+  virtual void StopWatching(base::WaitableEvent* done) OVERRIDE;
+
+  // For use by the FileWatcherDelegate.
+  void OnFilePathError(const FilePath& path);
+  void OnFilePathChanged(const FilePath& path);
+
+ private:
+  friend class FileWatcherDelegate;
+
+  void ScheduleFallbackReloadTask();
+  void ScheduleReloadTask(const base::TimeDelta& delay);
+  void Reload();
+  bool IsSafeToReloadPolicy(const base::Time& now, base::TimeDelta* delay);
+  base::Time GetLastModification();
+
+  // Caller owns the value.
+  DictionaryValue* Load();
+
+  // Managed with a scoped_ptr rather than being declared as an inline member to
+  // decouple the watcher's life cycle from the loader's. This decoupling makes
+  // it possible to destroy the watcher before the loader's destructor is called
+  // (e.g. during Stop), since |watcher_| internally holds a reference to the
+  // loader and keeps it alive.
+  scoped_ptr<base::files::FilePathWatcher> watcher_;
+
+  // Records last known modification timestamp of |config_file_path_|.
+  base::Time last_modification_file_;
+
+  // The wall clock time at which the last modification timestamp was
+  // recorded.  It's better to not assume the file notification time and the
+  // wall clock times come from the same source, just in case there is some
+  // non-local filesystem involved.
+  base::Time last_modification_clock_;
+
+  scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
+  const FilePath config_dir_;
+  NatEnabledCallback nat_enabled_cb_;
+
+  bool current_nat_enabled_state_;
+  bool first_state_published_;
+
+  base::WeakPtrFactory<NatPolicyLinux> weak_factory_;
+};
+
+}  // namespace policy_hack
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_PLUGIN_POLICY_HACK_NAT_POLICY_LINUX_H_