public void SendPost(IPEndPoint destination, Uri uri, bool reliable, string content)
{
CoapMessageType type = CoapMessageType.NonConfirmable;
if (reliable)
{
type = CoapMessageType.Confirmable;
}
CoapMessage message = new CoapMessage(type, CoapMessageCode.POST);
message.Destination = destination;
message.Uri = uri;
message.Payload = content == null ? null : System.Text.Encoding.UTF8.GetBytes(content);
SendRequest(message);
}
public async Task HandleMessage(CoapMessage message)
{
await Task.Run(() => {});
Console.WriteLine("I'll do something at some point");
}
public Task HandleRequest(CoapMessage message)
{
throw new System.NotImplementedException();
}
public Task HandleResponse(CoapMessage response)
{
throw new System.NotImplementedException();
}
// TODO: build this kind of mechanism into handling a queue of tasks:
// https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/async/start-multiple-async-tasks-and-process-them-as-they-complete
// https://devblogs.microsoft.com/pfxteam/processing-tasks-as-they-complete/
public SendMessageStatus SendMessage(CoapMessage message)
{
message.DecomposeUri(message.Uri);
message.MessageID = (ushort)(idhash[0] << 8);
message.MessageID |= (ushort)idhash[1];
// prepare hasher for next message ID
idhash = hasher.ComputeHash(idhash);
SendMessageStatus status = SendMessageStatus.BusyQueued;
// TODO: move this to something that will check in the background - not as part of send! - check for any messages that are complete
List <Task> toRemove = new List <Task>();
foreach (Task t in messagesInProgress)
{
if (t.IsCompleted || t.IsCanceled || t.IsFaulted)
{
// TODO: do a bit more than this, handle errors
toRemove.Add(t);
}
}
foreach (Task t in toRemove)
{
messagesInProgress.Remove(t);
}
// TODO: if busy sending enqueue the message, make max configurable
if (messagesInProgress.Count > 100)
{
// too busy, queue the message and move on
outgoingQueue.Enqueue(message);
status = SendMessageStatus.BusyQueued;
}
else
{
// TODO: generate tokens and whatever needed to fulfill the protocol
// encode the message into a byte array
byte[] datagram = message.ToByteArray();
// attempt to send the message
Task <int> t = null;
t = endpoint.SendAsync(datagram, datagram.Length, message.Destination);
if (t.IsCompleted)
{
status = SendMessageStatus.SentImmediately;
}
else
{
Console.WriteLine($"Didn't send immediately so putting on progress list to check");
status = SendMessageStatus.Sending;
messagesInProgress.Add(t);
}
}
// TODO: kick queue
return(status);
}
public async Task HandleEmptyMessage(CoapMessage Request)
{
await Task.Run(() => {});
Console.WriteLine("I received a response to a message");
}
public static CoapMessage FromByteArray(byte[] bytes, IPEndPoint remoteEndpoint)
{
int pos = 0;
if (bytes.Length < 4)
{
throw new CoapMessageFormatException("Not enough data to form a valid header");
}
// header processing
CoapMessage message = new CoapMessage();
// need to do this now because we might need the endpoint and port for the url
message.Source = remoteEndpoint;
byte b = bytes[pos++];
message.Version = (byte)((b & 0xc0) >> 6);
message.Type = (CoapMessageType)((b & 0x30000000) >> 4);
message.TokenLength = (byte)((b & 0x0f000000));
if (message.TokenLength > 8)
{
throw new CoapMessageFormatException("Token length must be 0-8 bytes in length.");
}
b = bytes[pos++];
message.Code = (CoapMessageCode)b;
b = bytes[pos++];
message.MessageID = (UInt16)(b << 8);
b = bytes[pos++];
message.MessageID |= b;
if (message.TokenLength > 0)
{
message.TokenValue = new byte[message.TokenLength];
Array.Copy(bytes, pos, message.TokenValue, 0, message.TokenLength);
pos += message.TokenLength;
}
bool processingOptions = true;
int optionNumber = 0;
int optionLength = 0;
while (pos < bytes.Length && processingOptions)
{
if (bytes[pos] == 0xff)
{
pos++;
processingOptions = false;
// process payload
int payloadLength = bytes.Length - pos;
if (payloadLength == 0)
{
throw new CoapMessageFormatException("Payload marker cannot be followed by no payload");
}
if (payloadLength > 0)
{
message.Payload = new byte[payloadLength];
Array.Copy(bytes, pos, message.Payload, 0, payloadLength);
}
}
if (processingOptions)
{
int delta = (char)((bytes[pos] & 0xf0) >> 4);
optionLength = (char)(bytes[pos] & 0x0f);
pos++;
switch (delta)
{
case 13:
{
byte extendedDelta = bytes[pos++];
optionNumber += (extendedDelta + 13);
}
break;
case 14:
{
UInt16 extendedDelta = (UInt16)bytes[pos++];
extendedDelta <<= 8;
extendedDelta |= bytes[pos++];
optionNumber += (extendedDelta + 269);
}
break;
case 15:
if (bytes[pos] == 0xff)
{
processingOptions = false;
}
else
{
throw new CoapMessageFormatException("Malformed payload marker or invalid option");
}
break;
default:
optionNumber += delta;
break;
}
switch (optionLength)
{
case 13:
{
byte extendedLength = bytes[pos++];
optionLength = (extendedLength + 13);
}
break;
case 14:
{
UInt16 extendedLength = (UInt16)bytes[pos++];
extendedLength <<= 8;
extendedLength |= bytes[pos++];
optionLength = (extendedLength + 269);
}
break;
case 15:
{
}
break;
}
// TODO: based on table in 5.10 process options according to format and store in subclasses according to type
// switch (optionNumber)
// {
// case 1:
// { // If-Match - opaque - 0-8
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 3:
// { // Uri-Host - string - 1-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 4:
// { // ETag - opaque - 1-8
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 5:
// { // If-None-Match - empty - 0
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 7:
// { // Uri-Port - uint - 0-2
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 8:
// { // Location-Path - string - 0-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 11:
// { // Uri-Path - string - 0-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 12:
// { // Content-Format - uint - 0-2
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 14:
// { // Max-Age - uint - 0-4
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 15:
// { // Uri-Query - string - 0-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 17:
// { // Accept - uint - 0-2
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 20:
// { // Location-Query - string - 0-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 35:
// { // Proxy-Uri - string - 1-1034
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 39:
// { // Proxy-Scheme - string - 1-255
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// case 60:
// { // Size1 - uint - 0-4
// byte[] value = new byte[optionLength];
// Array.Copy(bytes, pos, value, 0, optionLength);
// }
// break;
// }
byte[] value = new byte[optionLength];
Array.Copy(bytes, pos, value, 0, optionLength);
pos += optionLength;
// add value as option
if (message.Options == null)
{
message.Options = new SortedDictionary <CoapOptionNumber, List <CoapOption> >();
}
if (!message.Options.ContainsKey((CoapOptionNumber)optionNumber))
{
message.Options[(CoapOptionNumber)optionNumber] = new List <CoapOption>();
}
CoapOption option = new CoapOption();
option.Number = optionNumber;
option.Length = optionLength;
option.Value = value;
message.Options[(CoapOptionNumber)optionNumber].Add(option);
}
}
// construct URL for easier processing by consumers
message.Uri = message.ComposeUri();
return(message);
}
