/// <summary>
/// Create a new CoAP messages with <see cref="CoapMessageCode"/> set based on the type of <see cref="Exception"/> provided.
/// </summary>
/// <remarks>
/// <see cref="CoapMessage"/>.<see cref="Code"/> will be set to <see cref="CoapMessageCode.InternalServerError"/> by default unless:
/// <list type="bullet">
/// <item>
/// <description>When <paramref name="exception"/> is of type <see cref="CoapException"/>. Then <see cref="CoapMessage"/>.<see cref="Code"/> will be set to <see cref="CoapException"/>.<see cref="CoapException.ResponseCode"/></description>
/// </item>
/// <item>
/// <description>When <paramref name="exception"/> is of type <see cref="NotImplementedException"/>. Then <see cref="CoapMessage"/>.<see cref="Code"/> will be set to <see cref="CoapMessageCode.NotImplemented"/></description>
/// </item>
/// </list>
/// </remarks>
/// <param name="exception"></param>
/// <returns></returns>
public static CoapMessage FromException(Exception exception)
{
var result = new CoapMessage
{
Type = CoapMessageType.Reset,
Code = CoapMessageCode.InternalServerError,
Options = { new ContentFormat(ContentFormatType.TextPlain) },
Payload = Encoding.UTF8.GetBytes(exception.Message)
};
switch (exception)
{
case CoapException coapEx:
result.Code = coapEx.ResponseCode;
break;
case NotImplementedException _:
result.Code = CoapMessageCode.NotImplemented;
break;
}
return(result);
}
/// <summary>
/// Attempts to read the entire body of the block-wise message. Using the <paramref name="originalRequest"/> to request blocks.
/// </summary>
/// <param name="message">A message containing a <see cref="Block2"/> option.</param>
/// <param name="client"></param>
/// <param name="originalRequest">The orignal request which the block-wise response was for.</param>
/// <returns>The completed body for the block-wise messages.</returns>
public static byte[] GetCompletedBlockWisePayload(this CoapMessage message, CoapClient client, CoapMessage originalRequest)
{
var block2 = message.Options.Get <Options.Block2>()
?? throw new ArgumentException($"{nameof(CoapMessage)} does not contain a {nameof(Options.Block2)} option", nameof(message));
if (originalRequest == null)
{
throw new ArgumentNullException("Please provide original requesting message", nameof(originalRequest));
}
if (block2.BlockNumber != 0)
{
throw new CoapBlockException($"Can not get completed payload starting with block {block2.BlockNumber}. Please start from 0");
}
var memoryStream = new MemoryStream();
using (var reader = new CoapBlockStreamReader(client, message, originalRequest))
reader.CopyTo(memoryStream);
return(memoryStream.ToArray());
}
/// <summary>
/// Creates an <see cref="CoapException"/> with details populated from <paramref name="message"/> with an optional inner-exception.
/// </summary>
/// <param name="message"></param>
/// <param name="innerExcpetion"></param>
/// <returns></returns>
public static CoapException FromCoapMessage(CoapMessage message, Exception innerExcpetion = null)
{
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
var errorMessage = $"({message.Code.Class}.{message.Code.Detail:D2})";
var contentFormat = message.Options.Get <Options.ContentFormat>();
if (contentFormat != null && message.Payload != null)
{
if (contentFormat.MediaType == Options.ContentFormatType.TextPlain)
{
errorMessage += System.Text.Encoding.UTF8.GetString(message.Payload);
}
else
{
errorMessage += string.Join(", ", message.Payload.Select(b => $"0x{b:X2}"));
}
}
return(new CoapException(errorMessage, innerExcpetion, message.Code));
}
/// <summary> /// <see cref="SendAsync(CoapMessage, ICoapEndpoint, CancellationToken)"/> /// </summary> /// <param name="message"></param> /// <param name="endpoint"></param> /// <returns></returns> public virtual async Task <int> SendAsync(CoapMessage message, ICoapEndpoint endpoint) => await SendAsync(message, endpoint, CancellationToken.None);
/// <summary> /// <see cref="SendAsync(CoapMessage, ICoapEndpoint, CancellationToken)"/> /// </summary> /// <param name="message"></param> /// <param name="token"></param> /// <returns></returns> public virtual async Task <int> SendAsync(CoapMessage message, CancellationToken token) => await SendAsync(message, null, token);
private async Task ReceiveAsyncInternal()
{
try
{
while (true)
{
if (Endpoint == null)
{
return;
}
var payload = await Endpoint.ReceiveAsync();
var message = new CoapMessage(Endpoint.IsMulticast);
try
{
message.Deserialise(payload.Payload);
}
catch (CoapMessageFormatException)
{
if (message.Type == CoapMessageType.Confirmable &&
!Endpoint.IsMulticast)
{
await SendAsync(new CoapMessage
{
Id = message.Id,
Type = CoapMessageType.Reset
}, payload.Endpoint);
}
throw;
}
if (_messageResponses.ContainsKey(message.Id))
{
_messageResponses[message.Id].TrySetResult(message);
}
lock (_receiveQueue)
{
_receiveQueue.Enqueue(Task.FromResult(new CoapReceiveResult(payload.Endpoint, message)));
}
_receiveEvent.Set();
}
}
catch (Exception ex)
{
if (ex is CoapEndpointException)
{
Endpoint?.Dispose();
Endpoint = null;
foreach (var response in _messageResponses.Values)
{
response.TrySetCanceled();
}
}
lock (_receiveQueue)
{
// Gona cheat and enque that exception so it gets thrown as if this detached-infinite-loop never existed...
_receiveQueue.Enqueue(Task.FromException <CoapReceiveResult>(ex));
}
_receiveEvent.Set();
}
}
public static CoapBlockWiseContext CreateBlockWiseContext(this CoapMessage message, CoapClient client, CoapMessage response = null)
{
if (!message.Code.IsRequest())
{
throw new ArgumentException($"A block-Wise context requires a base request message. Message code {message.Code} is invalid.", nameof(message));
}
if (response != null && response.Code.IsRequest())
{
throw new ArgumentException($"A block-Wise context response can not be set from a message code {message.Code}.", nameof(response));
}
return(new CoapBlockWiseContext(client, message, response));
}
public static CoapMessageIdentifier GetIdentifier(this CoapMessage message, ICoapEndpoint endpoint = null, bool isRequest = false) => new CoapMessageIdentifier(message, endpoint, isRequest);
public virtual Task <CoapMessage> DeleteAsync(CoapMessage request, ICoapConnectionInformation connectionInformation) => DeleteAsync(request);
public virtual Task <CoapMessage> PostAsync(CoapMessage request) => Task.FromResult(Post(request));
/// <summary> /// <see cref="SendAsync(CoapMessage, ICoapEndpoint, CancellationToken)"/> /// </summary> /// <param name="message"></param> /// <returns></returns> public virtual async Task <CoapMessageIdentifier> SendAsync(CoapMessage message) => await SendAsync(message, null, CancellationToken.None);
/// <summary> /// Checks if a <see cref="CoapReceiveResult"/> has been received for the coresponding <paramref name="request"/> and returns it. /// Otherwise waits until a new result is received unless cancelled by the <paramref name="token"/> or the <see cref="MaxRetransmitAttempts"/> is reached. /// </summary> /// <param name="request">Waits for a result with a coresponding request message.</param> /// <param name="token">Token to cancel the blocking Receive operation</param> /// <returns>Valid result if a result is received, <c>null</c> if canceled.</returns> /// <exception cref="CoapClientException">If the timeout period * maximum retransmission attempts was reached.</exception> public Task <CoapMessage> GetResponseAsync(CoapMessage request, ICoapEndpoint endpoint = null, bool isRequest = false, CancellationToken token = default(CancellationToken), bool dequeue = true) => GetResponseAsync(request.GetIdentifier(endpoint, isRequest), token, dequeue);
private async Task ReceiveAsyncInternal()
{
var isMulticast = Endpoint?.IsMulticast ?? false;
try
{
while (true)
{
Task <CoapPacket> payloadTask;
lock (this)
{
if (Endpoint == null)
{
return;
}
payloadTask = Endpoint.ReceiveAsync(_receiveTaskCTS.Token);
}
var payload = await payloadTask;
var receivedAt = DateTime.Now;
var message = new CoapMessage {
IsMulticast = isMulticast
};
try
{
message.FromBytes(payload.Payload);
// Ignore non-empty reset messages
if (message.Type == CoapMessageType.Reset && message.Code != CoapMessageCode.None)
{
continue;
}
// Reject confirmable empty messages
if (message.Type == CoapMessageType.Confirmable && message.Code == CoapMessageCode.None)
{
await SendAsync(new CoapMessage { Id = message.Id, Type = CoapMessageType.Reset }, payload.Endpoint);
continue;
}
// Ignore repeated messages
if (IsRepeated(payload.Endpoint, message.Id))
{
continue;
}
}
catch (CoapMessageFormatException)
{
if (message.Type == CoapMessageType.Confirmable &&
!isMulticast)
{
await SendAsync(new CoapMessage
{
Id = message.Id,
Type = CoapMessageType.Reset
}, payload.Endpoint);
}
if (message.Type == CoapMessageType.Acknowledgement &&
Coap.ReservedMessageCodeClasses.Contains(message.Code.Class))
{
continue;
}
throw;
}
lock (_recentMessages)
{
var messageId = message.GetIdentifier(payload.Endpoint);
if (_messageResponses.ContainsKey(messageId))
{
_messageResponses[messageId].TrySetResult(message);
}
_recentMessages.Enqueue(Tuple.Create(receivedAt, payload.Endpoint, message));
}
_receiveQueue.Enqueue(Task.FromResult(new CoapReceiveResult(payload.Endpoint, message)));
_receiveEvent.Set();
}
}
catch (Exception ex)
{
if (ex is CoapEndpointException)
{
var endpoint = Endpoint;
lock (this)
Endpoint = null;
endpoint?.Dispose();
foreach (var response in _messageResponses.Values)
{
response.TrySetCanceled();
}
}
// Gona cheat and enque that exception so it gets thrown as if this detached-infinite-loop never existed...
_receiveQueue.Enqueue(Task.FromException <CoapReceiveResult>(ex));
_receiveEvent.Set();
}
}
public virtual Task <int> PostAsync(string uri, CoapMessage message, ICoapEndpoint endpoint = null)
{
throw new NotImplementedException();
}
public virtual Task <CoapMessage> DeleteAsync(CoapMessage request) => Task.FromResult(Delete(request));
public CoapReceiveResult(ICoapEndpoint endpoint, CoapMessage message)
{
Endpoint = endpoint;
Message = message;
}
/// <summary>
/// Checks if a <see cref="CoapMessage"/> is part ofa block-wise transfer by checking for the presence of either <see cref="CoAPNet.Options.Block1"/> or <see cref="CoAPNet.Options.Block2"/>.
/// </summary>
/// <param name="message"></param>
/// <returns><c>true</c> when <paramref name="message"/> is part of a Block-Wise transfer</returns>
public static bool IsBlockWise(this CoapMessage message)
{
return(message.Options.Any(o => o.OptionNumber == CoapRegisteredOptionNumber.Block1 || o.OptionNumber == CoapRegisteredOptionNumber.Block2));
}
