CODEWITHSUNDEEP
c#socketsudp
Andrew Zak
Andrew Zak

Reputation: 69

A request to send or receive data was disallowed because the socket is not connected - when sending data

I am trying to send data back to the client when the server receives "debug". ATM the following provides this error:

A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied.

Added my main class to help answer questions

    static Socket newSocket;
    static byte[] data;
    static EndPoint tmpRemote;
    static IPEndPoint sender, endpoint;
    static int recv;
    static void Main(string[] args)
    {
        data = new byte[1024];

        endpoint = new IPEndPoint(IPAddress.Any, 3000);

        newSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

        newSocket.Bind(endpoint);



        sender = new IPEndPoint(IPAddress.Any, 904);
        tmpRemote = (EndPoint)sender;

        newSocket.BeginReceiveFrom(data, 0, data.Length, SocketFlags.None, ref tmpRemote, new AsyncCallback(OperatorCallBack), data);

        Console.Read();
    }



    private static void OperatorCallBack(IAsyncResult ar)
    {
        log("[" + DateTime.Now + "][New Connection] " + tmpRemote.ToString() + "");
        try
        {
            int size = newSocket.EndReceiveFrom(ar, ref tmpRemote);
            if (size > 0)
            {
                data = (byte[])ar.AsyncState;
                string[] dataCommand = Encoding.ASCII.GetString(data, 0, size).Split(' ');
                if (dataCommand[0] == "debug")
                {
                    newSocket.Send(Encoding.ASCII.GetBytes("HA IT WORKED :)"));
                    log("Sent debug");
                }
                else
                {
                    log("Invalid Command");
                }
            }
            data = new byte[1024];
            newSocket.BeginReceiveFrom(data, 0, data.Length, SocketFlags.None, ref tmpRemote, new AsyncCallback(OperatorCallBack), data);
        }
        catch (Exception exp)
        {
            Console.WriteLine(exp.Message);
        }
    }

Upvotes: 4

Views: 52593

Answers (4)

da jowkar
da jowkar

Reputation: 311

I had similar issues when trying to connect to sockets over a slow connection. I resolved it by this code before call receive:

            for (int i = 0; i < 50; i++)
            {
                if (!client.Connected)
                {
                    Thread.Sleep(50);
                }
                else
                {
                    break;
                }
            }

            if (!client.Connected)
            {
                SendMessage("Unable to connect to network!");
            }
            

            // Begin receiving the data from the remote device.  
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReceiveCallback), state);

Upvotes: 0

Abzkn
Abzkn

Reputation: 51

As connection(socket.connect()) is not needed when you send data via ProtocolType.Udp that error may occur when you dont suggest the address wher UDP Message should forward

IN YOUR CASE here the address is not provided for udp Send()

SOLUTION

Try SendTo() instead

Socket soc = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
soc.EnableBroadcast = true;
IPEndPoint ipend = new IPEndPoint(IPAddress.Broadcast, 58717);
EndPoint endp = (EndPoint)ipend;
byte[] bytes = new byte[1024];

bytes = Encoding.ASCII.GetBytes(str);

soc.SendTo(bytes,ipend);

soc.Close();

Upvotes: 3

Peter Beeby
Peter Beeby

Reputation: 61

I had similar issues when trying to connect to sockets over a slow connection. I resolved it by making sure the newSocket.Connected property was true before any Send/Receive calls.

Upvotes: 3

user207421
user207421

Reputation: 311050

The error message is quite clear. You are calling send() on an unconnected socket and without providing a target address. Where are you sending to? UDP doesn't know.

Upvotes: 2

Related Questions