private void Discover(JObject parameters)
{
var major = parameters["majorDeviceClass"]?.ToObject <BluetoothMajorClass>();
var minor = parameters["minorDeviceClass"]?.ToObject <BluetoothMinorClass>();
if (major == null || minor == null)
{
throw JsonRpcException.InvalidParams("majorDeviceClass and minorDeviceClass required");
}
var deviceClass = BluetoothClassOfDevice.FromParts(major.Value, minor.Value,
BluetoothServiceCapabilities.None);
var selector = BluetoothDevice.GetDeviceSelectorFromClassOfDevice(deviceClass);
try
{
_watcher = DeviceInformation.CreateWatcher(selector, new List <String>
{
SignalStrengthPropertyName,
IsPresentPropertyName,
BluetoothAddressPropertyName
});
_watcher.Added += PeripheralDiscovered;
_watcher.EnumerationCompleted += EnumerationCompleted;
_watcher.Updated += PeripheralUpdated;
_watcher.Stopped += EnumerationStopped;
_watcher.Start();
}
catch (ArgumentException)
{
throw JsonRpcException.ApplicationError("Failed to create device watcher");
}
}
/// <summary>
/// Handle the client's request to read the value of a particular service characteristic.
/// </summary>
/// <param name="parameters">
/// The IDs of the service & characteristic, an optional encoding to be used in the response, and an optional
/// flag to request notification of future changes to this characteristic's value.
/// </param>
/// <returns>
/// The current value as a JSON object with a "message" property and optional "encoding" property
/// </returns>
private async Task <JToken> Read(JObject parameters)
{
var endpoint = await GetEndpoint("read request", parameters, GattHelpers.BlockListStatus.ExcludeReads);
//Console.Write("-->" +endpoint.AttributeHandle);
var encoding = parameters.TryGetValue("encoding", out var encodingToken)
? encodingToken?.ToObject <string>() // possibly null and that's OK
: "base64";
var startNotifications = parameters["startNotifications"]?.ToObject <bool>() ?? false;
var readResult = await endpoint.ReadValueAsync(BluetoothCacheMode.Uncached);
if (startNotifications)
{
await StartNotifications(endpoint, encoding);
}
switch (readResult.Status)
{
case GattCommunicationStatus.Success:
// Calling ToArray() on a buffer of length 0 throws an ArgumentException
var resultBytes = readResult.Value.Length > 0 ? readResult.Value.ToArray() : new byte[0];
return(EncodingHelpers.EncodeBuffer(resultBytes, encoding));
case GattCommunicationStatus.Unreachable:
throw JsonRpcException.ApplicationError("destination unreachable");
default:
throw JsonRpcException.ApplicationError($"unknown result from read: {readResult.Status}");
}
}
/// <summary>
/// Handle the client's request to connect to a particular peripheral.
/// Valid in the discovery state; transitions to connected state on success.
/// </summary>
/// <param name="parameters">
/// A JSON object containing the UUID of a peripheral found by the most recent discovery request
/// </param>
private async Task Connect(JObject parameters)
{
if (_services != null)
{
throw JsonRpcException.InvalidRequest("already connected to peripheral");
}
var peripheralId = parameters["peripheralId"].ToObject <ulong>();
if (!_reportedPeripherals.Contains(peripheralId))
{
// the client may only connect to devices that were returned by the current discovery request
throw JsonRpcException.InvalidParams($"invalid peripheral ID: {peripheralId}");
}
_peripheral = await BluetoothLEDevice.FromBluetoothAddressAsync(peripheralId);
var servicesResult = await _peripheral.GetGattServicesAsync(BluetoothCacheMode.Uncached);
if (servicesResult.Status != GattCommunicationStatus.Success)
{
throw JsonRpcException.ApplicationError($"failed to enumerate GATT services: {servicesResult.Status}");
}
_peripheral.ConnectionStatusChanged += OnPeripheralStatusChanged;
_services = servicesResult.Services;
// cache all characteristics in all services
foreach (var service in _services)
{
var characteristicsResult = await service.GetCharacteristicsAsync(BluetoothCacheMode.Uncached);
if (characteristicsResult.Status != GattCommunicationStatus.Success)
{
continue;
}
foreach (var characteristic in characteristicsResult.Characteristics)
{
_cachedCharacteristics.Add(characteristic.Uuid, characteristic);
}
}
// collect optional services plus all services from all filters
// Note: this modifies _optionalServices for convenience since we know it'll go away soon.
_allowedServices = _optionalServices ?? new HashSet <Guid>();
_allowedServices = _filters
.Where(filter => filter.RequiredServices?.Count > 0)
.Aggregate(_allowedServices, (result, filter) =>
{
result.UnionWith(filter.RequiredServices);
return(result);
});
// clean up resources used by discovery
_watcher.Stop();
_watcher = null;
_reportedPeripherals.Clear();
_optionalServices = null;
}
private static async void ListenForMessages(string id)
{
try
{
DataReader _socketReader = s_readerMap[id];
DataWriter _socketWriter = s_writerMap[id];
while (true)
{
await _socketReader.LoadAsync(sizeof(UInt16));
var messageSize = _socketReader.ReadUInt16();
var headerBytes = BitConverter.GetBytes(messageSize);
var messageBytes = new byte[messageSize];
await _socketReader.LoadAsync(messageSize);
_socketReader.ReadBytes(messageBytes);
var totalBytes = new byte[headerBytes.Length + messageSize];
Array.Copy(headerBytes, totalBytes, headerBytes.Length);
Array.Copy(messageBytes, 0, totalBytes, headerBytes.Length, messageSize);
var parameters = EncodingHelpers.EncodeBuffer(totalBytes, "base64");
s_currentSession.SendRemoteRequest("didReceiveMessage", parameters);
}
}
catch (Exception e)
{
await s_currentSession.SendErrorNotification(JsonRpcException.ApplicationError("Peripheral connection closed"));
Debug.Print($"Closing connection to peripheral: {e.Message}");
//Dispose();
}
}
/// <summary>
/// Handle the client's request to write a value to a particular service characteristic.
/// </summary>
/// <param name="parameters">
/// The IDs of the service & characteristic along with the message and optionally the message encoding.
/// </param>
/// <returns>The number of decoded bytes written</returns>
private async Task <JToken> Write(JObject parameters)
{
var buffer = EncodingHelpers.DecodeBuffer(parameters);
var endpoint = await GetEndpoint("write request", parameters, GattHelpers.BlockListStatus.ExcludeWrites);
Console.Write(endpoint.AttributeHandle);
Console.Write(" ");
foreach (byte bt in buffer)
{
Console.Write(bt + " ");
}
Console.WriteLine("");
var withResponse = (parameters["withResponse"]?.ToObject <bool>() ?? false) ||
!endpoint.CharacteristicProperties.HasFlag(GattCharacteristicProperties.WriteWithoutResponse);
var result = await endpoint.WriteValueWithResultAsync(buffer.AsBuffer(),
withResponse?GattWriteOption.WriteWithResponse : GattWriteOption.WriteWithoutResponse);
switch (result.Status)
{
case GattCommunicationStatus.Success:
return(buffer.Length);
case GattCommunicationStatus.ProtocolError:
throw JsonRpcException.ApplicationError($"Error while attempting to write: {result.Status} {result.ProtocolError}"); // "ProtocolError 3"
default:
throw JsonRpcException.ApplicationError($"Error while attempting to write: {result.Status}"); // "Unreachable"
}
}
private async Task Connect(JObject parameters)
{
//if (_connectedSocket?.Information.RemoteHostName != null)
//{
// throw JsonRpcException.InvalidRequest("Already connected");
//}
var id = parameters["peripheralId"]?.ToObject <string>();
var address = Convert.ToUInt64(id, 16);
var bluetoothDevice = await BluetoothDevice.FromBluetoothAddressAsync(address);
if (!bluetoothDevice.DeviceInformation.Pairing.IsPaired)
{
if (parameters.TryGetValue("pin", out var pin))
{
_pairingCode = (string)pin;
}
var pairingResult = await Pair(bluetoothDevice);
if (pairingResult != DevicePairingResultStatus.Paired &&
pairingResult != DevicePairingResultStatus.AlreadyPaired)
{
throw JsonRpcException.ApplicationError("Could not automatically pair with peripheral");
}
}
s_currentSession = this;
if (s_connectMap.ContainsKey(id))
{
// ListenForMessages(id);
return;
}
var services = await bluetoothDevice.GetRfcommServicesForIdAsync(RfcommServiceId.SerialPort,
BluetoothCacheMode.Uncached);
if (services.Services.Count > 0)
{
StreamSocket _connectedSocket = new StreamSocket();
await _connectedSocket.ConnectAsync(services.Services[0].ConnectionHostName,
services.Services[0].ConnectionServiceName);
DataWriter _socketWriter = new DataWriter(_connectedSocket.OutputStream);
DataReader _socketReader = new DataReader(_connectedSocket.InputStream)
{
ByteOrder = ByteOrder.LittleEndian
};
s_readerMap.Add(id, _socketReader);
s_writerMap.Add(id, _socketWriter);
s_connectMap.Add(id, _connectedSocket);
ListenForMessages(id);
}
else
{
throw JsonRpcException.ApplicationError("Cannot read services from peripheral");
}
}
private async Task StartNotifications(GattCharacteristic endpoint, string encoding)
{
if (!_notifyCharacteristics.Contains(endpoint))
{
endpoint.ValueChanged += OnValueChanged;
var notificationRequestResult = await endpoint.WriteClientCharacteristicConfigurationDescriptorAsync(
GattClientCharacteristicConfigurationDescriptorValue.Notify);
if (notificationRequestResult != GattCommunicationStatus.Success)
{
endpoint.ValueChanged -= OnValueChanged;
throw JsonRpcException.ApplicationError(
$"could not start notifications: {notificationRequestResult}");
}
_notifyCharacteristics.Add(endpoint);
}
}
// See https://webbluetoothcg.github.io/web-bluetooth/#bluetoothlescanfilterinit-canonicalizing
internal BLEScanFilter(JToken filter)
{
var filterObject = (JObject)filter;
JToken token;
if (filterObject.TryGetValue("name", out token))
{
Name = token.ToString();
}
if (filterObject.TryGetValue("namePrefix", out token))
{
NamePrefix = token.ToString();
}
if (filterObject.TryGetValue("services", out token))
{
var serviceArray = (JArray)token;
RequiredServices = new HashSet <Guid>(serviceArray.Select(GattHelpers.GetServiceUuid));
if (RequiredServices.Count < 1)
{
throw JsonRpcException.InvalidParams($"filter contains empty or invalid services list: {filter}");
}
}
if (filterObject.TryGetValue("manufacturerData", out token))
{
ManufacturerData = new Dictionary <int, BLEDataFilter>();
var manufacturerData = (JObject)token;
foreach (var kv in manufacturerData)
{
var manufacturerId = int.Parse(kv.Key);
var dataFilter = new BLEDataFilter(kv.Value);
ManufacturerData.Add(manufacturerId, dataFilter);
}
}
if (filterObject.TryGetValue("serviceData", out token))
{
throw JsonRpcException.ApplicationError("filtering on serviceData is not currently supported");
}
}
/// <summary>
/// Handle the client's request to write a value to a particular service characteristic.
/// </summary>
/// <param name="parameters">
/// The IDs of the service & characteristic along with the message and optionally the message encoding.
/// </param>
/// <returns>The number of decoded bytes written</returns>
private async Task <JToken> Write(JObject parameters)
{
var buffer = EncodingHelpers.DecodeBuffer(parameters);
var endpoint = await GetEndpoint("write request", parameters, GattHelpers.BlockListStatus.ExcludeWrites);
var withResponse = (parameters["withResponse"]?.ToObject <bool>() ?? false) ||
!endpoint.CharacteristicProperties.HasFlag(GattCharacteristicProperties.WriteWithoutResponse);
var result = await endpoint.WriteValueAsync(buffer.AsBuffer(),
withResponse?GattWriteOption.WriteWithResponse : GattWriteOption.WriteWithoutResponse);
switch (result)
{
case GattCommunicationStatus.Success:
return(buffer.Length);
case GattCommunicationStatus.Unreachable:
throw JsonRpcException.ApplicationError("destination unreachable");
default:
throw JsonRpcException.ApplicationError($"unknown result from write: {result}");
}
}
// See https://webbluetoothcg.github.io/web-bluetooth/#bluetoothlescanfilterinit-canonicalizing
internal BLEScanFilter(JToken filter)
{
var filterObject = (JObject)filter;
JToken token;
if (filterObject.TryGetValue("name", out token))
{
Name = token.ToString();
}
if (filterObject.TryGetValue("namePrefix", out token))
{
NamePrefix = token.ToString();
}
if (filterObject.TryGetValue("services", out token))
{
var serviceArray = (JArray)token;
RequiredServices = new HashSet <Guid>(serviceArray.Select(GattHelpers.GetServiceUuid));
if (RequiredServices.Count < 1)
{
throw JsonRpcException.InvalidParams($"filter contains empty or invalid services list: {filter}");
}
}
if (filterObject.TryGetValue("manufacturerData", out token))
{
throw JsonRpcException.ApplicationError("filtering on manufacturerData is not currently supported");
}
if (filterObject.TryGetValue("serviceData", out token))
{
throw JsonRpcException.ApplicationError("filtering on serviceData is not currently supported");
}
}
private async Task DidReceiveResponse(JObject response)
{
var requestId = response["id"]?.ToObject <RequestId?>();
if (!requestId.HasValue)
{
throw JsonRpcException.InvalidRequest("response ID value missing or wrong type");
}
if (!_completionHandlers.TryGetValue(requestId.Value, out var completionHandler))
{
throw JsonRpcException.InvalidRequest("response ID does not correspond to any open request");
}
var error = response["error"]?.ToObject <JsonRpcException>();
try
{
if (error != null)
{
await completionHandler(null, error);
}
else
{
var result = response["result"];
await completionHandler(result, null);
}
}
catch (Exception e)
{
var remoteMessage = $"exception encountered while handling response {requestId}";
Debug.Print(remoteMessage);
Debug.Print($"The exception was: {e}");
throw JsonRpcException.ApplicationError(remoteMessage);
}
}
/// <summary>
/// Fetch the characteristic referred to in the endpointInfo object and perform access verification.
/// </summary>
/// <param name="errorContext">
/// A string to include in error reporting, if an error is encountered
/// </param>
/// <param name="endpointInfo">
/// A JSON object which may contain a 'serviceId' property and a 'characteristicId' property
/// </param>
/// <param name="checkFlag">
/// Check if this flag is set for this service or characteristic in the block list. If so, throw.
/// </param>
/// <returns>
/// The specified GATT service characteristic, if it can be resolved and all checks pass.
/// Otherwise, a JSON-RPC exception is thrown indicating what went wrong.
/// </returns>
private async Task <GattCharacteristic> GetEndpoint(string errorContext, JObject endpointInfo,
GattHelpers.BlockListStatus checkFlag)
{
GattDeviceService service;
Guid?serviceId;
if (_peripheral.ConnectionStatus != BluetoothConnectionStatus.Connected)
{
throw JsonRpcException.ApplicationError($"Peripheral is not connected for {errorContext}");
}
if (endpointInfo.TryGetValue("serviceId", out var serviceToken))
{
serviceId = GattHelpers.GetServiceUuid(serviceToken);
service = _services?.FirstOrDefault(s => s.Uuid == serviceId);
}
else
{
service = _services?.FirstOrDefault(); // could in theory be null
serviceId = service?.Uuid;
}
if (!serviceId.HasValue)
{
throw JsonRpcException.InvalidParams($"Could not determine service UUID for {errorContext}");
}
//if (_allowedServices?.Contains(serviceId.Value) != true)
//{
// throw JsonRpcException.InvalidParams($"attempt to access unexpected service: {serviceId}");
//}
var blockStatus = GattHelpers.GetBlockListStatus(serviceId.Value);
if (blockStatus.HasFlag(checkFlag))
{
throw JsonRpcException.InvalidParams($"service is block-listed with {blockStatus}: {serviceId}");
}
if (service == null)
{
throw JsonRpcException.InvalidParams($"could not find service {serviceId}");
}
GattCharacteristic characteristic;
Guid?characteristicId;
if (endpointInfo.TryGetValue("characteristicId", out var characteristicToken))
{
characteristic = null; // we will attempt to collect this below
characteristicId = GattHelpers.GetCharacteristicUuid(characteristicToken);
}
else
{
if (!_cachedServiceCharacteristics.TryGetValue(service.Uuid, out var characteristics))
{
var characteristicsResult = await service.GetCharacteristicsAsync(BluetoothCacheMode.Uncached);
if (characteristicsResult.Status != GattCommunicationStatus.Success)
{
throw JsonRpcException.ApplicationError(
$"failed to collect characteristics from service: {characteristicsResult.Status}");
}
characteristics = characteristicsResult.Characteristics;
_cachedServiceCharacteristics.Add(service.Uuid, characteristics);
}
characteristic = characteristics.FirstOrDefault(); // could in theory be null
characteristicId = characteristic?.Uuid;
}
if (!characteristicId.HasValue)
{
throw JsonRpcException.InvalidParams($"Could not determine characteristic UUID for {errorContext}");
}
blockStatus = GattHelpers.GetBlockListStatus(characteristicId.Value);
if (blockStatus.HasFlag(checkFlag))
{
throw JsonRpcException.InvalidParams(
$"characteristic is block-listed with {blockStatus}: {characteristicId}");
}
// collect the characteristic if we didn't do so above
if (characteristic == null &&
!_cachedCharacteristics.TryGetValue(characteristicId.Value, out characteristic))
{
var characteristicsResult =
await service.GetCharacteristicsForUuidAsync(characteristicId.Value, BluetoothCacheMode.Uncached);
if (characteristicsResult.Status != GattCommunicationStatus.Success)
{
throw JsonRpcException.ApplicationError(
$"failed to collect characteristics from service: {characteristicsResult.Status}");
}
if (characteristicsResult.Characteristics.Count < 1)
{
throw JsonRpcException.InvalidParams(
$"could not find characteristic {characteristicId} on service {serviceId}");
}
// TODO: why is this a list?
characteristic = characteristicsResult.Characteristics[0];
_cachedCharacteristics.Add(characteristicId.Value, characteristic);
}
try
{
// Unfortunately there's no direct way to test if the peripheral object has been disposed. The
// `connectionState` property still indicates that the peripheral is connected in some cases, for
// example when Bluetooth is turned off in Bluetooth settings / Control Panel. However, trying to
// access the `Service` property of the `Characteristic` will throw an `ObjectDisposedException` in
// this case, so that's the hack being used here to check for a disposed peripheral.
var tempDisposalProbe = characteristic.Service;
}
catch (ObjectDisposedException e)
{
// This could mean that Bluetooth was turned off or the computer resumed from sleep
throw JsonRpcException.ApplicationError($"Peripheral is disposed for {errorContext}");
}
return(characteristic);
}
private async Task DidReceiveMessage(string message, Func <string, Task> sendResponseText)
{
var encoding = Encoding.UTF8;
JToken responseId = null;
async Task SendResponseInternal(JToken result, JsonRpcException error)
{
var response = MakeResponse(responseId, result, error);
var responseText = JsonConvert.SerializeObject(response);
Console.WriteLine("REP:" + responseText);
await sendResponseText(responseText);
}
async Task SendResponse(JToken result, JsonRpcException error)
{
try
{
await SendResponseInternal(result, error);
}
catch (Exception firstError)
{
try
{
Debug.Print($"Could not encode response: {firstError}");
await SendResponseInternal(null,
JsonRpcException.ApplicationError("Could not encode response"));
}
catch (Exception secondError)
{
Debug.Print($"Could not report response encoding failure: {secondError}");
}
}
}
try
{
Console.WriteLine("Rec:" + message);
var json = JObject.Parse(message);
// do this as early as possible so that error responses can include it.
responseId = json["id"];
// property "jsonrpc" must be exactly "2.0"
if ((string)json["jsonrpc"] != "2.0")
{
throw JsonRpcException.InvalidRequest("unrecognized JSON-RPC version string");
}
if (json["method"] != null)
{
await DidReceiveRequest(json, async result => await SendResponse(result, null));
}
else if (json["result"] != null || json["error"] != null)
{
await DidReceiveResponse(json);
}
else
{
throw JsonRpcException.InvalidRequest("message is neither request nor response");
}
}
catch (JsonRpcException jsonRpcException)
{
await SendResponse(null, jsonRpcException);
}
catch (Exception e)
{
var jsonRpcException =
JsonRpcException.ApplicationError($"Unhandled error encountered during call: {e}");
await SendResponse(null, jsonRpcException);
}
}
/// <summary>
/// Fetch the characteristic referred to in the endpointInfo object and perform access verification.
/// </summary>
/// <param name="errorContext">
/// A string to include in error reporting, if an error is encountered
/// </param>
/// <param name="endpointInfo">
/// A JSON object which may contain a 'serviceId' property and a 'characteristicId' property
/// </param>
/// <param name="checkFlag">
/// Check if this flag is set for this service or characteristic in the block list. If so, throw.
/// </param>
/// <returns>
/// The specified GATT service characteristic, if it can be resolved and all checks pass.
/// Otherwise, a JSON-RPC exception is thrown indicating what went wrong.
/// </returns>
private async Task <GattCharacteristic> GetEndpoint(string errorContext, JObject endpointInfo,
GattHelpers.BlockListStatus checkFlag)
{
GattDeviceService service;
Guid?serviceId;
if (endpointInfo.TryGetValue("serviceId", out var serviceToken))
{
serviceId = GattHelpers.GetServiceUuid(serviceToken);
service = _services?.FirstOrDefault(s => s.Uuid == serviceId);
}
else
{
service = _services?.FirstOrDefault(); // could in theory be null
serviceId = service?.Uuid;
}
if (!serviceId.HasValue)
{
throw JsonRpcException.InvalidParams($"Could not determine service UUID for {errorContext}");
}
if (_allowedServices?.Contains(serviceId.Value) != true)
{
throw JsonRpcException.InvalidParams($"attempt to access unexpected service: {serviceId}");
}
var blockStatus = GattHelpers.GetBlockListStatus(serviceId.Value);
if (blockStatus.HasFlag(checkFlag))
{
throw JsonRpcException.InvalidParams($"service is block-listed with {blockStatus}: {serviceId}");
}
if (service == null)
{
throw JsonRpcException.InvalidParams($"could not find service {serviceId}");
}
GattCharacteristic characteristic;
Guid?characteristicId;
if (endpointInfo.TryGetValue("characteristicId", out var characteristicToken))
{
characteristic = null; // we will attempt to collect this below
characteristicId = GattHelpers.GetCharacteristicUuid(characteristicToken);
}
else
{
if (!_cachedServiceCharacteristics.TryGetValue(service.Uuid, out var characteristics))
{
var characteristicsResult = await service.GetCharacteristicsAsync(BluetoothCacheMode.Uncached);
if (characteristicsResult.Status != GattCommunicationStatus.Success)
{
throw JsonRpcException.ApplicationError(
$"failed to collect characteristics from service: {characteristicsResult.Status}");
}
characteristics = characteristicsResult.Characteristics;
_cachedServiceCharacteristics.Add(service.Uuid, characteristics);
}
characteristic = characteristics.FirstOrDefault(); // could in theory be null
characteristicId = characteristic?.Uuid;
}
if (!characteristicId.HasValue)
{
throw JsonRpcException.InvalidParams($"Could not determine characteristic UUID for {errorContext}");
}
blockStatus = GattHelpers.GetBlockListStatus(characteristicId.Value);
if (blockStatus.HasFlag(checkFlag))
{
throw JsonRpcException.InvalidParams(
$"characteristic is block-listed with {blockStatus}: {characteristicId}");
}
// collect the characteristic if we didn't do so above
if (characteristic == null &&
!_cachedCharacteristics.TryGetValue(characteristicId.Value, out characteristic))
{
var characteristicsResult =
await service.GetCharacteristicsForUuidAsync(characteristicId.Value, BluetoothCacheMode.Uncached);
if (characteristicsResult.Status != GattCommunicationStatus.Success)
{
throw JsonRpcException.ApplicationError(
$"failed to collect characteristics from service: {characteristicsResult.Status}");
}
if (characteristicsResult.Characteristics.Count < 1)
{
throw JsonRpcException.InvalidParams(
$"could not find characteristic {characteristicId} on service {serviceId}");
}
// TODO: why is this a list?
characteristic = characteristicsResult.Characteristics[0];
_cachedCharacteristics.Add(characteristicId.Value, characteristic);
}
return(characteristic);
}