/// <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);
}
/// <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);
}
