Add Device Policy Handler for Bluetooth, and allow disabling the Bluetooth adapter on Chrome OS

device/bluetooth/bluetooth_adapter_bluez.h

 // 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.
 
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_ADAPTER_BLUEZ_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_ADAPTER_BLUEZ_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 68 matching lines @@
 
   // BluetoothAdapter:
   void Shutdown() override;
   std::string GetAddress() const override;
   std::string GetName() const override;
   void SetName(const std::string& name,
                const base::Closure& callback,
                const ErrorCallback& error_callback) override;
   bool IsInitialized() const override;
   bool IsPresent() const override;
+  void SetDisabled(bool disabled) override;
   bool IsPowered() const override;
   void SetPowered(bool powered,
                   const base::Closure& callback,
                   const ErrorCallback& error_callback) override;
   bool IsDiscoverable() const override;
   void SetDiscoverable(bool discoverable,
                        const base::Closure& callback,
                        const ErrorCallback& error_callback) override;
   bool IsDiscovering() const override;
   void CreateRfcommService(
@@ skipping 240 matching lines @@
   // ended (with either success or failure).
   void ProcessQueuedDiscoveryRequests();
 
   InitCallback init_callback_;
 
   bool initialized_;
 
   // Set in |Shutdown()|, makes IsPresent()| return false.
   bool dbus_is_shutdown_;
 
+  // Set in |SetDisabled()|, makes |IsPresent()| return false
+  // (just disables the interface, doesn't actually shut it down).
+  bool is_disabled_;

[ortuno, 2016/04/13 21:12:21]

I don't think this is the right place to store this. BluetoothAdapter is only
alive as long as someone holds a reference to it. If everyone drops their
references to it and it gets destroyed no one will be able to use the adapter
because the policy will not be set to true again.

[Ivan Šandrk, 2016/04/14 18:08:48]

In my code, I call SetDisabled through
device::BluetoothAdapterFactory::GetAdapter, which fetches the BluetoothAdapter
(and creates one if it doesn't exist) so this shouldn't be an issue.

But you have raised a valid point, something else goes wrong. If the
BluetoothAdapter gets disabled through SetDisabled, then afterwards all the
references go away and BluetoothAdapter is destroyed, then someone uses
BluetoothAdapter again and a new instance gets created, the new instance won't
be disabled.

This may not be a problem tho, as many pieces of code hold references to the
BluetoothAdapter and some have sufficiently long lifetimes (I have to check
this). Maybe the best solution is that I keep a reference to it myself, that way
I'm sure? What is your opinion on this?

[scheib, 2016/04/14 21:41:10]

You'll need to hold a reference to keep it disabled.

[Ivan Šandrk, 2016/04/15 17:32:06]

Done.

+
   // Number of discovery sessions that have been added.
   int num_discovery_sessions_;
 
   // True, if there is a pending request to start or stop discovery.
   bool discovery_request_pending_;
 
   // List of queued requests to add new discovery sessions. While there is a
   // pending request to BlueZ to start or stop discovery, many requests from
   // within Chrome to start or stop discovery sessions may occur. We only
   // queue requests to add new sessions to be processed later. All requests to
@@ skipping 27 matching lines @@
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<BluetoothAdapterBlueZ> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothAdapterBlueZ);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_ADAPTER_BLUEZ_H_