extensions/browser/api/usb/usb_event_router.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/browser/api/usb/usb_event_router.h"
   6
   7 #include "device/core/device_client.h"
   8 #include "device/usb/usb_device.h"
   9 #include "extensions/browser/api/device_permissions_manager.h"
  10 #include "extensions/browser/api/usb/usb_guid_map.h"
  11 #include "extensions/browser/event_router_factory.h"
  12 #include "extensions/common/api/usb.h"
  13 #include "extensions/common/permissions/permissions_data.h"
  14 #include "extensions/common/permissions/usb_device_permission.h"
  15
  16 namespace usb = extensions::api::usb;
  17
  18 using content::BrowserThread;
  19 using device::UsbDevice;
  20 using device::UsbService;
  21
  22 namespace extensions {
  23
  24 namespace {
  25
  26 // Returns true iff the given extension has permission to receive events
  27 // regarding this device.
  28 bool WillDispatchDeviceEvent(scoped_refptr<UsbDevice> device,
  29                              content::BrowserContext* browser_context,
  30                              const Extension* extension,
  31                              Event* event,
  32                              const base::DictionaryValue* listener_filter) {
  33   // Check install-time and optional permissions.
  34   UsbDevicePermission::CheckParam param(
  35       device->vendor_id(), device->product_id(),
  36       UsbDevicePermissionData::UNSPECIFIED_INTERFACE);
  37   if (extension->permissions_data()->CheckAPIPermissionWithParam(
  38           APIPermission::kUsbDevice, &param)) {
  39     return true;
  40   }
  41
  42   // Check permissions granted through chrome.usb.getUserSelectedDevices.
  43   DevicePermissions* device_permissions =
  44       DevicePermissionsManager::Get(browser_context)
  45           ->GetForExtension(extension->id());
  46   if (device_permissions->FindUsbDeviceEntry(device).get()) {
  47     return true;
  48   }
  49
  50   return false;
  51 }
  52
  53 base::LazyInstance<BrowserContextKeyedAPIFactory<UsbEventRouter>>::Leaky
  54     g_event_router_factory = LAZY_INSTANCE_INITIALIZER;
  55
  56 }  // namespace
  57
  58 // static
  59 BrowserContextKeyedAPIFactory<UsbEventRouter>*
  60 UsbEventRouter::GetFactoryInstance() {
  61   return g_event_router_factory.Pointer();
  62 }
  63
  64 UsbEventRouter::UsbEventRouter(content::BrowserContext* browser_context)
  65     : browser_context_(browser_context), observer_(this) {
  66   EventRouter* event_router = EventRouter::Get(browser_context_);
  67   if (event_router) {
  68     event_router->RegisterObserver(this, usb::OnDeviceAdded::kEventName);
  69     event_router->RegisterObserver(this, usb::OnDeviceRemoved::kEventName);
  70   }
  71 }
  72
  73 UsbEventRouter::~UsbEventRouter() {
  74 }
  75
  76 void UsbEventRouter::Shutdown() {
  77   EventRouter* event_router = EventRouter::Get(browser_context_);
  78   if (event_router) {
  79     event_router->UnregisterObserver(this);
  80   }
  81 }
  82
  83 void UsbEventRouter::OnListenerAdded(const EventListenerInfo& details) {
  84   UsbService* service = device::DeviceClient::Get()->GetUsbService();
  85   if (!observer_.IsObserving(service)) {
  86     observer_.Add(service);
  87   }
  88 }
  89
  90 void UsbEventRouter::OnDeviceAdded(scoped_refptr<device::UsbDevice> device) {
  91   DispatchEvent(usb::OnDeviceAdded::kEventName, device);
  92 }
  93
  94 void UsbEventRouter::OnDeviceRemoved(scoped_refptr<device::UsbDevice> device) {
  95   DispatchEvent(usb::OnDeviceRemoved::kEventName, device);
  96 }
  97
  98 void UsbEventRouter::DispatchEvent(const std::string& event_name,
  99                                    scoped_refptr<UsbDevice> device) {
 100   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 101   EventRouter* event_router = EventRouter::Get(browser_context_);
 102   if (event_router) {
 103     usb::Device device_obj;
 104     UsbGuidMap::Get(browser_context_)->GetApiDevice(device, &device_obj);
 105
 106     scoped_ptr<Event> event;
 107     if (event_name == usb::OnDeviceAdded::kEventName) {
 108       event.reset(new Event(events::USB_ON_DEVICE_ADDED,
 109                             usb::OnDeviceAdded::kEventName,
 110                             usb::OnDeviceAdded::Create(device_obj)));
 111     } else {
 112       DCHECK(event_name == usb::OnDeviceRemoved::kEventName);
 113       event.reset(new Event(events::USB_ON_DEVICE_REMOVED,
 114                             usb::OnDeviceRemoved::kEventName,
 115                             usb::OnDeviceRemoved::Create(device_obj)));
 116     }
 117
 118     event->will_dispatch_callback =
 119         base::Bind(&WillDispatchDeviceEvent, device);
 120     event_router->BroadcastEvent(event.Pass());
 121   }
 122 }
 123
 124 template <>
 125 void BrowserContextKeyedAPIFactory<
 126     UsbEventRouter>::DeclareFactoryDependencies() {
 127   DependsOn(DevicePermissionsManagerFactory::GetInstance());
 128   DependsOn(EventRouterFactory::GetInstance());
 129   DependsOn(UsbGuidMap::GetFactoryInstance());
 130 }
 131
 132 }  // extensions