DBus changes for implementing local GATT attributes.

device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider_impl.cc

+// Copyright 2016 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 "device/bluetooth/dbus/bluetooth_gatt_characteristic_service_provider_impl.h"
+
+#include <stddef.h>
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/strings/string_util.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+namespace bluez {
+
+namespace {
+
+const char kErrorInvalidArgs[] = "org.freedesktop.DBus.Error.InvalidArgs";
+const char kErrorPropertyReadOnly[] =
+    "org.freedesktop.DBus.Error.PropertyReadOnly";
+const char kErrorFailed[] = "org.freedesktop.DBus.Error.Failed";
+
+}  // namespace
+
+BluetoothGattCharacteristicServiceProviderImpl::
+    BluetoothGattCharacteristicServiceProviderImpl(
+        dbus::Bus* bus,
+        const dbus::ObjectPath& object_path,
+        std::unique_ptr<BluetoothGattAttributeValueDelegate> delegate,
+        const std::string& uuid,
+        const std::vector<std::string>& flags,
+        const std::vector<std::string>& permissions,
+        const dbus::ObjectPath& service_path)
+    : origin_thread_id_(base::PlatformThread::CurrentId()),
+      uuid_(uuid),
+      bus_(bus),
+      delegate_(std::move(delegate)),
+      object_path_(object_path),
+      service_path_(service_path),
+      weak_ptr_factory_(this) {
+  VLOG(1) << "Created Bluetooth GATT characteristic: " << object_path.value()
+          << " UUID: " << uuid;
+  DCHECK(bus_);
+  DCHECK(delegate_);
+  DCHECK(!uuid_.empty());
+  DCHECK(object_path_.IsValid());
+  DCHECK(service_path_.IsValid());
+  DCHECK(base::StartsWith(object_path_.value(), service_path_.value() + "/",
+                          base::CompareCase::SENSITIVE));
+
+  exported_object_ = bus_->GetExportedObject(object_path_);
+
+  exported_object_->ExportMethod(
+      dbus::kDBusPropertiesInterface, dbus::kDBusPropertiesGet,
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::Get,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnExported,
+                 weak_ptr_factory_.GetWeakPtr()));
+
+  exported_object_->ExportMethod(
+      dbus::kDBusPropertiesInterface, dbus::kDBusPropertiesSet,
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::Set,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnExported,
+                 weak_ptr_factory_.GetWeakPtr()));
+
+  exported_object_->ExportMethod(
+      dbus::kDBusPropertiesInterface, dbus::kDBusPropertiesGetAll,
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::GetAll,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnExported,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+BluetoothGattCharacteristicServiceProviderImpl::
+    ~BluetoothGattCharacteristicServiceProviderImpl() {
+  VLOG(1) << "Cleaning up Bluetooth GATT characteristic: "
+          << object_path_.value();
+  if (bus_)
+    bus_->UnregisterExportedObject(object_path_);
+}
+
+BluetoothGattCharacteristicServiceProviderImpl::
+    BluetoothGattCharacteristicServiceProviderImpl(
+        const dbus::ObjectPath& object_path,
+        const std::string& uuid,
+        const dbus::ObjectPath& service_path)
+    : origin_thread_id_(base::PlatformThread::CurrentId()),
+      uuid_(uuid),
+      bus_(nullptr),
+      delegate_(nullptr),
+      object_path_(object_path),
+      service_path_(service_path),
+      weak_ptr_factory_(this) {}
+
+void BluetoothGattCharacteristicServiceProviderImpl::SendValueChanged(
+    const std::vector<uint8_t>& value) {
+  VLOG(2) << "Emitting a PropertiesChanged signal for characteristic value.";
+  dbus::Signal signal(dbus::kDBusPropertiesInterface,
+                      dbus::kDBusPropertiesChangedSignal);
+  dbus::MessageWriter writer(&signal);
+  dbus::MessageWriter array_writer(NULL);
+  dbus::MessageWriter dict_entry_writer(NULL);
+  dbus::MessageWriter variant_writer(NULL);
+
+  // interface_name
+  writer.AppendString(
+      bluetooth_gatt_characteristic::kBluetoothGattCharacteristicInterface);
+
+  // changed_properties
+  writer.OpenArray("{sv}", &array_writer);
+  array_writer.OpenDictEntry(&dict_entry_writer);
+  dict_entry_writer.AppendString(bluetooth_gatt_characteristic::kValueProperty);
+  dict_entry_writer.OpenVariant("ay", &variant_writer);
+  variant_writer.AppendArrayOfBytes(value.data(), value.size());
+  dict_entry_writer.CloseContainer(&variant_writer);
+  array_writer.CloseContainer(&dict_entry_writer);
+  writer.CloseContainer(&array_writer);
+
+  // invalidated_properties.
+  writer.OpenArray("s", &array_writer);
+  writer.CloseContainer(&array_writer);
+
+  exported_object_->SendSignal(&signal);
+}
+
+// Returns true if the current thread is on the origin thread.
+bool BluetoothGattCharacteristicServiceProviderImpl::OnOriginThread() {
+  return base::PlatformThread::CurrentId() == origin_thread_id_;
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::Get(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  VLOG(2) << "BluetoothGattCharacteristicServiceProvider::Get: "
+          << object_path_.value();
+  DCHECK(OnOriginThread());
+
+  dbus::MessageReader reader(method_call);
+
+  std::string interface_name;
+  std::string property_name;
+  if (!reader.PopString(&interface_name) || !reader.PopString(&property_name) ||
+      reader.HasMoreData()) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(method_call, kErrorInvalidArgs,
+                                            "Expected 'ss'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Only the GATT characteristic interface is supported.
+  if (interface_name !=
+      bluetooth_gatt_characteristic::kBluetoothGattCharacteristicInterface) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(
+            method_call, kErrorInvalidArgs,
+            "No such interface: '" + interface_name + "'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // If getting the "Value" property, obtain the value from the delegate.
+  if (property_name == bluetooth_gatt_characteristic::kValueProperty) {
+    DCHECK(delegate_);
+    delegate_->GetValue(
+        base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnGet,
+                   weak_ptr_factory_.GetWeakPtr(), method_call,
+                   response_sender),
+        base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
+                   weak_ptr_factory_.GetWeakPtr(), method_call,
+                   response_sender));
+    return;
+  }
+
+  std::unique_ptr<dbus::Response> response =
+      dbus::Response::FromMethodCall(method_call);
+  dbus::MessageWriter writer(response.get());
+  dbus::MessageWriter variant_writer(NULL);
+
+  // TODO(armansito): Process the "Flags" and "Permissions" properties below.
+  if (property_name == bluetooth_gatt_characteristic::kUUIDProperty) {
+    writer.OpenVariant("s", &variant_writer);
+    variant_writer.AppendString(uuid_);
+    writer.CloseContainer(&variant_writer);
+  } else if (property_name == bluetooth_gatt_characteristic::kServiceProperty) {
+    writer.OpenVariant("o", &variant_writer);
+    variant_writer.AppendObjectPath(service_path_);
+    writer.CloseContainer(&variant_writer);
+  } else {
+    response = dbus::ErrorResponse::FromMethodCall(
+        method_call, kErrorInvalidArgs,
+        "No such property: '" + property_name + "'.");
+  }
+
+  response_sender.Run(std::move(response));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::Set(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  VLOG(2) << "BluetoothGattCharacteristicServiceProvider::Set: "
+          << object_path_.value();
+  DCHECK(OnOriginThread());
+
+  dbus::MessageReader reader(method_call);
+
+  std::string interface_name;
+  std::string property_name;
+  dbus::MessageReader variant_reader(NULL);
+  if (!reader.PopString(&interface_name) || !reader.PopString(&property_name) ||
+      !reader.PopVariant(&variant_reader) || reader.HasMoreData()) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(method_call, kErrorInvalidArgs,
+                                            "Expected 'ssv'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Only the GATT characteristic interface is allowed.
+  if (interface_name !=
+      bluetooth_gatt_characteristic::kBluetoothGattCharacteristicInterface) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(
+            method_call, kErrorInvalidArgs,
+            "No such interface: '" + interface_name + "'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Only the "Value" property is writeable.
+  if (property_name != bluetooth_gatt_characteristic::kValueProperty) {
+    std::string error_name;
+    std::string error_message;
+    if (property_name == bluetooth_gatt_characteristic::kUUIDProperty ||
+        property_name == bluetooth_gatt_characteristic::kServiceProperty) {
+      error_name = kErrorPropertyReadOnly;
+      error_message = "Read-only property: '" + property_name + "'.";
+    } else {
+      error_name = kErrorInvalidArgs;
+      error_message = "No such property: '" + property_name + "'.";
+    }
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(method_call, error_name,
+                                            error_message);
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Obtain the value.
+  const uint8_t* bytes = NULL;
+  size_t length = 0;
+  if (!variant_reader.PopArrayOfBytes(&bytes, &length)) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(
+            method_call, kErrorInvalidArgs,
+            "Property '" + property_name + "' has type 'ay'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Pass the set request onto the delegate.
+  std::vector<uint8_t> value(bytes, bytes + length);
+  DCHECK(delegate_);
+  delegate_->SetValue(
+      value,
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnSet,
+                 weak_ptr_factory_.GetWeakPtr(), method_call, response_sender),
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
+                 weak_ptr_factory_.GetWeakPtr(), method_call, response_sender));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::GetAll(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  VLOG(2) << "BluetoothGattCharacteristicServiceProvider::GetAll: "
+          << object_path_.value();
+  DCHECK(OnOriginThread());
+
+  dbus::MessageReader reader(method_call);
+
+  std::string interface_name;
+  if (!reader.PopString(&interface_name) || reader.HasMoreData()) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(method_call, kErrorInvalidArgs,
+                                            "Expected 's'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Only the GATT characteristic interface is supported.
+  if (interface_name !=
+      bluetooth_gatt_characteristic::kBluetoothGattCharacteristicInterface) {
+    std::unique_ptr<dbus::ErrorResponse> error_response =
+        dbus::ErrorResponse::FromMethodCall(
+            method_call, kErrorInvalidArgs,
+            "No such interface: '" + interface_name + "'.");
+    response_sender.Run(std::move(error_response));
+    return;
+  }
+
+  // Try to obtain the value from the delegate. We will construct the
+  // response in the success callback.
+  DCHECK(delegate_);
+  delegate_->GetValue(
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnGetAll,
+                 weak_ptr_factory_.GetWeakPtr(), method_call, response_sender),
+      base::Bind(&BluetoothGattCharacteristicServiceProviderImpl::OnFailure,
+                 weak_ptr_factory_.GetWeakPtr(), method_call, response_sender));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::OnExported(
+    const std::string& interface_name,
+    const std::string& method_name,
+    bool success) {
+  LOG_IF(WARNING, !success) << "Failed to export " << interface_name << "."
+                            << method_name;
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::OnGetAll(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender,
+    const std::vector<uint8_t>& value) {
+  VLOG(2) << "Characteristic value obtained from delegate. Responding to "
+          << "GetAll.";
+
+  std::unique_ptr<dbus::Response> response =
+      dbus::Response::FromMethodCall(method_call);
+  dbus::MessageWriter writer(response.get());
+  WriteProperties(&writer, &value);
+  response_sender.Run(std::move(response));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::WriteProperties(
+    dbus::MessageWriter* writer,
+    const std::vector<uint8_t>* value) {
+  dbus::MessageWriter array_writer(NULL);
+  dbus::MessageWriter dict_entry_writer(NULL);
+  dbus::MessageWriter variant_writer(NULL);
+
+  writer->OpenArray("{sv}", &array_writer);
+
+  array_writer.OpenDictEntry(&dict_entry_writer);
+  dict_entry_writer.AppendString(bluetooth_gatt_characteristic::kUUIDProperty);
+  dict_entry_writer.AppendVariantOfString(uuid_);
+  array_writer.CloseContainer(&dict_entry_writer);
+
+  array_writer.OpenDictEntry(&dict_entry_writer);
+  dict_entry_writer.AppendString(
+      bluetooth_gatt_characteristic::kServiceProperty);
+  dict_entry_writer.AppendVariantOfObjectPath(service_path_);
+  array_writer.CloseContainer(&dict_entry_writer);
+
+  if (value) {
+    array_writer.OpenDictEntry(&dict_entry_writer);
+    dict_entry_writer.AppendString(
+        bluetooth_gatt_characteristic::kValueProperty);
+    dict_entry_writer.OpenVariant("ay", &variant_writer);
+    variant_writer.AppendArrayOfBytes(value->data(), value->size());
+    dict_entry_writer.CloseContainer(&variant_writer);
+    array_writer.CloseContainer(&dict_entry_writer);
+  }
+
+  // TODO(armansito): Process Flags & Permissions properties.
+
+  writer->CloseContainer(&array_writer);
+};
+
+void BluetoothGattCharacteristicServiceProviderImpl::OnGet(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender,
+    const std::vector<uint8_t>& value) {
+  VLOG(2) << "Returning characteristic value obtained from delegate.";
+  std::unique_ptr<dbus::Response> response =
+      dbus::Response::FromMethodCall(method_call);
+  dbus::MessageWriter writer(response.get());
+  dbus::MessageWriter variant_writer(NULL);
+
+  writer.OpenVariant("ay", &variant_writer);
+  variant_writer.AppendArrayOfBytes(value.data(), value.size());
+  writer.CloseContainer(&variant_writer);
+
+  response_sender.Run(std::move(response));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::OnSet(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  VLOG(2) << "Successfully set characteristic value. Return success.";
+  response_sender.Run(dbus::Response::FromMethodCall(method_call));
+}
+
+void BluetoothGattCharacteristicServiceProviderImpl::OnFailure(
+    dbus::MethodCall* method_call,
+    dbus::ExportedObject::ResponseSender response_sender) {
+  VLOG(2) << "Failed to get/set characteristic value. Report error.";
+  std::unique_ptr<dbus::ErrorResponse> error_response =
+      dbus::ErrorResponse::FromMethodCall(
+          method_call, kErrorFailed, "Failed to get/set characteristic value.");
+  response_sender.Run(std::move(error_response));
+}
+
+const dbus::ObjectPath&
+BluetoothGattCharacteristicServiceProviderImpl::object_path() const {
+  return object_path_;
+}
+
+}  // namespace bluez