bluetooth: Browser-side implementation of getCharacteristic

content/browser/bluetooth/bluetooth_dispatcher_host.cc

Index: content/browser/bluetooth/bluetooth_dispatcher_host.cc
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.cc b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
index c11c203b13ee8b60fef83d7ab6a95605b04b30db..924974f6be8bb395992a1bbd8a5de1721df12ae0 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.cc
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
@@ -10,10 +10,12 @@
 #include "device/bluetooth/bluetooth_adapter_factory.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_discovery_session.h"
+#include "device/bluetooth/bluetooth_gatt_characteristic.h"
 #include "device/bluetooth/bluetooth_gatt_service.h"
 
 using device::BluetoothAdapter;
 using device::BluetoothAdapterFactory;
+using device::BluetoothGattCharacteristic;
 using device::BluetoothGattService;
 
 namespace content {
@@ -54,6 +56,7 @@ bool BluetoothDispatcherHost::OnMessageReceived(const IPC::Message& message) {
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_RequestDevice, OnRequestDevice)
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_ConnectGATT, OnConnectGATT)
   IPC_MESSAGE_HANDLER(BluetoothHostMsg_GetPrimaryService, OnGetPrimaryService)
+  IPC_MESSAGE_HANDLER(BluetoothHostMsg_GetCharacteristic, OnGetCharacteristic)
   IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -149,6 +152,57 @@ void BluetoothDispatcherHost::OnGetPrimaryService(
       base::TimeDelta::FromSeconds(current_delay_time_));
 }
 
+void BluetoothDispatcherHost::OnGetCharacteristic(
+    int thread_id,
+    int request_id,
+    const std::string& service_instance_id,
+    const std::string& characteristic_uuid) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // There are no cases in which a normal renderer could pass

[scheib, 2015/06/04 06:30:48]

Move this comment either just above the 'if' line, or inside the conditional
block.
Reword:
 // A service_instance_id not in the map implies a hostile renderer
 // because a renderer obtains the service id from this class and
 // it will be added to the map at that time.

[ortuno, 2015/06/05 19:37:44]

Done.

+  // a service_instance_id not in our map so we can assume
+  // the renderer is hostile.
+  auto device_iter = service_to_device_.find(service_instance_id);
+  if (device_iter == service_to_device_.end()) {
+    BadMessageReceived();  // Kill the renderer.
+    return;
+  }
+
+  // TODO(ortuno): Check if domain has access to device.
+  // https://crbug.com/493459
+  device::BluetoothDevice* device =
+      adapter_->GetDevice(device_iter->second /* device_instance_id */);
+
+  if (device == NULL) {
+    Send(new BluetoothMsg_GetCharacteristicError(
+        thread_id, request_id, BluetoothError::NETWORK_ERROR));
+    return;
+  }
+
+  // TODO(ortuno): Check if domain has access to service
+  // http://crbug.com/493460
+  device::BluetoothGattService* service =
+      device->GetGattService(service_instance_id);
+  if (!service) {
+    Send(new BluetoothMsg_GetCharacteristicError(
+        thread_id, request_id, BluetoothError::NETWORK_ERROR));
+    return;
+  }
+
+  for (BluetoothGattCharacteristic* characteristic :
+       service->GetCharacteristics()) {
+    if (characteristic->GetUUID().canonical_value() == characteristic_uuid) {
+      // TODO(ortuno): Use generated instance ID instead.
+      // https://crbug.com/495379
+      Send(new BluetoothMsg_GetCharacteristicSuccess(
+          thread_id, request_id, characteristic->GetIdentifier()));
+      return;
+    }
+  }
+  Send(new BluetoothMsg_GetCharacteristicError(thread_id, request_id,
+                                               BluetoothError::NOT_FOUND));
+}
+
 void BluetoothDispatcherHost::OnDiscoverySessionStarted(
     int thread_id,
     int request_id,
@@ -253,8 +307,13 @@ void BluetoothDispatcherHost::OnServicesDiscovered(
   }
   for (BluetoothGattService* service : device->GetGattServices()) {
     if (service->GetUUID().canonical_value() == service_uuid) {
+      // TODO(ortuno): Use generated instance ID instead.
+      // https://crbug.com/495379
+      const std::string& service_identifier = service->GetIdentifier();
+      service_to_device_.insert(

[scheib, 2015/06/04 06:30:48]

Maybe for paranoia:

auto insert_result = service_to_device_.insert(
    make_pair(service_identifier, device_instance_id));
// DCHECK that insert found no previous entry, or entry value matches:
DCHECK(!insert_result.second 
    || insert_result.first.second == device_instance_id);

[ortuno, 2015/06/05 19:37:44]

If you call getPrimaryService("some uuid") twice the DCHECK would execute.

[scheib, 2015/06/08 17:02:07]

Whoops, overlooked this. Discussed in person too, but for record, this check is
that either it wasn't found in map, or if there was already an entry it checks
that the value stored already matches what we wanted to store.

+          make_pair(service_identifier, device_instance_id));
       Send(new BluetoothMsg_GetPrimaryServiceSuccess(thread_id, request_id,
-                                                     service->GetIdentifier()));
+                                                     service_identifier));
       return;
     }
   }